[PATCH] drm: restore is_master upon failure in drm_new_set_master() When drm_new_set_master() fails, we restore the old master, however we may have changed the is_master flag to 1, before failing, and it may be the case it was 0 previously. Restore also this flag to its original state, in case of failure. Here is a problematic flow: we check is_master in drm_is_current_master(), then proceed to ca