driver core: fix potential NULL pointer dereference in dev_uevent()

{
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "drivers/base/base.h",
                        "drivers/base/bus.c",
                        "drivers/base/core.c"
                    ],
                    "versions": [
                        {
                            "version": "16574dccd8f62dc1b585325f8a6a0aab10047ed8",
                            "lessThan": "abe56be73eb10a677d16066f65ff9d30251f5eee",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "16574dccd8f62dc1b585325f8a6a0aab10047ed8",
                            "lessThan": "2b344e779d9afd0fcb5ee4000e4d0fc7d8d867eb",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "16574dccd8f62dc1b585325f8a6a0aab10047ed8",
                            "lessThan": "3781e4b83e174364998855de777e184cf0b62c40",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "16574dccd8f62dc1b585325f8a6a0aab10047ed8",
                            "lessThan": "18daa52418e7e4629ed1703b64777294209d2622",
                            "status": "affected",
                            "versionType": "git"
                        }
                    ]
                }

{
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "affected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "drivers/base/base.h",
                        "drivers/base/bus.c",
                        "drivers/base/core.c"
                    ],
                    "versions": [
                        {
                            "version": "2.6.22",
                            "status": "affected"
                        },
                        {
                            "version": "0",
                            "lessThan": "2.6.22",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.6.89",
                            "lessThanOrEqual": "6.6.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.12.26",
                            "lessThanOrEqual": "6.12.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.14.5",
                            "lessThanOrEqual": "6.14.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.15",
                            "lessThanOrEqual": "*",
                            "status": "unaffected",
                            "versionType": "original_commit_for_fix"
                        }
                    ]
                }