CVE-2022-49485

drm/v3d: Fix null pointer dereference of pointer perfmon

In the Linux kernel, the following vulnerability has been resolved: drm/v3d: Fix null pointer dereference of pointer perfmon In the unlikely event that pointer perfmon is null the WARN_ON return path occurs after the pointer has already been deferenced. Fix this by only dereferencing perfmon after it has been null checked.