CVE-2024-50037 drm/fbdev-dma: Only cleanup deferred I/O if necessary

In the Linux kernel, the following vulnerability has been resolved: drm/fbdev-dma: Only cleanup deferred I/O if necessary Commit 5a498d4d06d6 "drm/fbdev-dma: Only install deferred I/O if necessary" initializes deferred I/O only if it is used. drmfbdevdmafbdestroy however calls fbdeferrediocleanup...