tcp: Use refcount_inc_not_zero() in tcp_twsk_unique().

{
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "net/ipv4/tcp_ipv4.c"
                    ],
                    "versions": [
                        {
                            "version": "ec94c2696f0bcd5ae92a553244e4ac30d2171a2d",
                            "lessThan": "84546cc1aeeb4df3e444b18a4293c9823f974be9",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "ec94c2696f0bcd5ae92a553244e4ac30d2171a2d",
                            "lessThan": "1796ca9c6f5bd50554214053af5f47d112818ee3",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "ec94c2696f0bcd5ae92a553244e4ac30d2171a2d",
                            "lessThan": "1d9cf07810c30ef7948879567d10fd1f01121d34",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "ec94c2696f0bcd5ae92a553244e4ac30d2171a2d",
                            "lessThan": "27b0284d8be182a81feb65581ab6a724dfd596e8",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "ec94c2696f0bcd5ae92a553244e4ac30d2171a2d",
                            "lessThan": "13ed7cdf079686ccd3618335205700c03f6fb446",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "ec94c2696f0bcd5ae92a553244e4ac30d2171a2d",
                            "lessThan": "6e48faad92be13166184d21506e4e54c79c13adc",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "ec94c2696f0bcd5ae92a553244e4ac30d2171a2d",
                            "lessThan": "517e32ea0a8c72202d0d8aa8df50a7cd3d6fdefc",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "ec94c2696f0bcd5ae92a553244e4ac30d2171a2d",
                            "lessThan": "f2db7230f73a80dbb179deab78f88a7947f0ab7e",
                            "status": "affected",
                            "versionType": "git"
                        }
                    ]
                }

{
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "affected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "net/ipv4/tcp_ipv4.c"
                    ],
                    "versions": [
                        {
                            "version": "4.16",
                            "status": "affected"
                        },
                        {
                            "version": "0",
                            "lessThan": "4.16",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "4.19.314",
                            "lessThanOrEqual": "4.19.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "5.4.276",
                            "lessThanOrEqual": "5.4.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "5.10.217",
                            "lessThanOrEqual": "5.10.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "5.15.159",
                            "lessThanOrEqual": "5.15.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.1.91",
                            "lessThanOrEqual": "6.1.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.6.31",
                            "lessThanOrEqual": "6.6.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.8.10",
                            "lessThanOrEqual": "6.8.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.9",
                            "lessThanOrEqual": "*",
                            "status": "unaffected",
                            "versionType": "original_commit_for_fix"
                        }
                    ]
                }