iommufd: Avoid locking internal accesses during unmap

{
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "drivers/iommu/iommufd/device.c"
                    ],
                    "versions": [
                        {
                            "version": "27b77ea5feaa8fcf385ea99ce757982b0ac9d1f0",
                            "lessThan": "436189ee4bb2c7c993b945d68570dd38c3e4349e",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "27b77ea5feaa8fcf385ea99ce757982b0ac9d1f0",
                            "lessThan": "50a66a63d1c841ae6b28a4551f642c1bba4c9529",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "27b77ea5feaa8fcf385ea99ce757982b0ac9d1f0",
                            "lessThan": "0dbcdf4473a614adbd732d567c9b39ac0e040e0c",
                            "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/iommu/iommufd/device.c"
                    ],
                    "versions": [
                        {
                            "version": "6.17",
                            "status": "affected"
                        },
                        {
                            "version": "0",
                            "lessThan": "6.17",
                            "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"
                        }
                    ]
                }