configfs: pin the symlink target's dirent instead of chasing ->ci_dentry

{
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "fs/configfs/symlink.c"
                    ],
                    "versions": [
                        {
                            "version": "7063fbf2261194f72ee75afca67b3b38b554b5fa",
                            "lessThan": "a44744454eafbc158e8c8e3ef8d207076410b195",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "7063fbf2261194f72ee75afca67b3b38b554b5fa",
                            "lessThan": "846ff40fd57a47e59a41f4e331ec3b34efaddc23",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "7063fbf2261194f72ee75afca67b3b38b554b5fa",
                            "lessThan": "4f54beb2e7f6d399396466682fba3539bcdcb414",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "7063fbf2261194f72ee75afca67b3b38b554b5fa",
                            "lessThan": "d47c5de1cd6bfbe1067fc310bf90e4e00205e839",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "7063fbf2261194f72ee75afca67b3b38b554b5fa",
                            "lessThan": "a7c1290eef60711c10289c056ad32ed1f2b47b12",
                            "status": "affected",
                            "versionType": "git"
                        }
                    ]
                }

{
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "affected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "fs/configfs/symlink.c"
                    ],
                    "versions": [
                        {
                            "version": "2.6.16",
                            "status": "affected"
                        },
                        {
                            "version": "0",
                            "lessThan": "2.6.16",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.6.160",
                            "lessThanOrEqual": "6.6.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.12.112",
                            "lessThanOrEqual": "6.12.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.18.53",
                            "lessThanOrEqual": "6.18.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.2.7",
                            "lessThanOrEqual": "7.2.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.3",
                            "lessThanOrEqual": "*",
                            "status": "unaffected",
                            "versionType": "original_commit_for_fix"
                        }
                    ]
                }