CVE-2026-74393 drm/syncobj: Fix memory leak in drm_syncobj_find_fence()

In the Linux kernel, the following vulnerability has been resolved: drm/syncobj: Fix memory leak in drmsyncobjfindfence Commit 18226ba52159 "drm/syncobj: reject invalid flags in drmsyncobjfindfence" forgot to take into account the fact that drmsyncobjfind takes a reference to syncobj and returns...