drm/mga200g: Use lockless gem BO free callback

No dev->struct_mutex anywhere to be seen.

Cc: Dave Airlie <airlied@redhat.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1464630800-30786-8-git-send-email-daniel.vetter@ffwll.ch

drivers/gpu/drm/mgag200/mgag200_drv.c

@@ -101,7 +101,7 @@ static struct drm_driver driver = {
 	.minor = DRIVER_MINOR,
 	.patchlevel = DRIVER_PATCHLEVEL,
 
-	.gem_free_object = mgag200_gem_free_object,
+	.gem_free_object_unlocked = mgag200_gem_free_object,
 	.dumb_create = mgag200_dumb_create,
 	.dumb_map_offset = mgag200_dumb_mmap_offset,
 	.dumb_destroy = drm_gem_dumb_destroy,