dm-pcache: only hand out initialized cache segments

{
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "drivers/md/dm-pcache/cache_segment.c"
                    ],
                    "versions": [
                        {
                            "version": "1d57628ff95b32d5cfa8d8f50e07690c161e9cf0",
                            "lessThan": "83e3116283ed2c6a6a1fa662862a4b4d7d2701a2",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "1d57628ff95b32d5cfa8d8f50e07690c161e9cf0",
                            "lessThan": "692037ae1a7cfacc2f0c22c6e034c1dfee0e553f",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "1d57628ff95b32d5cfa8d8f50e07690c161e9cf0",
                            "lessThan": "2df0fc042e299bae3c0f60ea5cd2af9285658e9f",
                            "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/md/dm-pcache/cache_segment.c"
                    ],
                    "versions": [
                        {
                            "version": "6.18",
                            "status": "affected"
                        },
                        {
                            "version": "0",
                            "lessThan": "6.18",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.18.50",
                            "lessThanOrEqual": "6.18.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.2.4",
                            "lessThanOrEqual": "7.2.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.3",
                            "lessThanOrEqual": "*",
                            "status": "unaffected",
                            "versionType": "original_commit_for_fix"
                        }
                    ]
                }