CVE-2024-26874 drm/mediatek: Fix a null pointer crash in mtk_drm_crtc_finish_page_flip

In the Linux kernel, the following vulnerability has been resolved: drm/mediatek: Fix a null pointer crash in mtkdrmcrtcfinishpageflip It's possible that mtkcrtc-event is NULL in mtkdrmcrtcfinishpageflip. pendingneedsvblank value is set by mtkcrtc-event, but in mtkdrmcrtcatomicflush, it's is not...