ublk: check import_ubuf() return value

{
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "drivers/block/ublk_drv.c"
                    ],
                    "versions": [
                        {
                            "version": "981f95a571e3ca20a496c0b77dbf6b06039c6648",
                            "lessThan": "7f97c762b5f6e0005c5c7d040ded73bf7fb3587e",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "981f95a571e3ca20a496c0b77dbf6b06039c6648",
                            "lessThan": "27ff6e8703f7a7160c728501da2f8ef8e7bb6b2f",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "981f95a571e3ca20a496c0b77dbf6b06039c6648",
                            "lessThan": "0121c84adb6a4cd6f7560b5895bd88f9899bbc1f",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "981f95a571e3ca20a496c0b77dbf6b06039c6648",
                            "lessThan": "5ac6019cb78e98c9608fda72726b36ddf8474dd7",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "981f95a571e3ca20a496c0b77dbf6b06039c6648",
                            "lessThan": "3831568792af75b6523fa93bb91560e29189cf55",
                            "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/block/ublk_drv.c"
                    ],
                    "versions": [
                        {
                            "version": "6.5",
                            "status": "affected"
                        },
                        {
                            "version": "0",
                            "lessThan": "6.5",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.6.160",
                            "lessThanOrEqual": "6.6.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.12.114",
                            "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"
                        }
                    ]
                }