drm/xe/oa: Zero OA buffer at allocation

{
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "drivers/gpu/drm/xe/xe_oa.c"
                    ],
                    "versions": [
                        {
                            "version": "392bf22238ff88506f410c464ba0c7a84e9de471",
                            "lessThan": "21f41b6daf0dbe2cdaaf9f54af6e23fd3c9190b9",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "392bf22238ff88506f410c464ba0c7a84e9de471",
                            "lessThan": "cd3e2918c247db631d88cdd704596d9d27e5513e",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "392bf22238ff88506f410c464ba0c7a84e9de471",
                            "lessThan": "fd8662823caa114a63f07222d2aa448f6ac5e864",
                            "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/gpu/drm/xe/xe_oa.c"
                    ],
                    "versions": [
                        {
                            "version": "6.11",
                            "status": "affected"
                        },
                        {
                            "version": "0",
                            "lessThan": "6.11",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.18.59",
                            "lessThanOrEqual": "6.18.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.2.13",
                            "lessThanOrEqual": "7.2.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.3",
                            "lessThanOrEqual": "*",
                            "status": "unaffected",
                            "versionType": "original_commit_for_fix"
                        }
                    ]
                }