media: v4l2-async: Unregister sub-device if asc_list is empty

{
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "drivers/media/v4l2-core/v4l2-async.c"
                    ],
                    "versions": [
                        {
                            "version": "28a1295795d85a25f2e7dd391c43969e95fcb341",
                            "lessThan": "c7201bd08cad791858337e33ffcd90d8ae4147c2",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "28a1295795d85a25f2e7dd391c43969e95fcb341",
                            "lessThan": "e190320cebe921f99973c984ac53f317061a011f",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "28a1295795d85a25f2e7dd391c43969e95fcb341",
                            "lessThan": "65e55f34fb2d61cb4f8a5dfcb93848af2aea0f32",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "28a1295795d85a25f2e7dd391c43969e95fcb341",
                            "lessThan": "9fb74dce5c650cb23b60f6ba0ffcd5024e948a75",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "28a1295795d85a25f2e7dd391c43969e95fcb341",
                            "lessThan": "4e72f13d58c4245c177a9d5f54579345554f354d",
                            "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/media/v4l2-core/v4l2-async.c"
                    ],
                    "versions": [
                        {
                            "version": "6.6",
                            "status": "affected"
                        },
                        {
                            "version": "0",
                            "lessThan": "6.6",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.6.157",
                            "lessThanOrEqual": "6.6.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.12.110",
                            "lessThanOrEqual": "6.12.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.18.52",
                            "lessThanOrEqual": "6.18.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.2.6",
                            "lessThanOrEqual": "7.2.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.3",
                            "lessThanOrEqual": "*",
                            "status": "unaffected",
                            "versionType": "original_commit_for_fix"
                        }
                    ]
                }