drm/sun4i: Use lockless gem BO free callback

No dev->struct_mutex anywhere to be seen.

Cc: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1464630800-30786-24-git-send-email-daniel.vetter@ffwll.ch

drivers/gpu/drm/sun4i/sun4i_drv.c

@@ -103,7 +103,7 @@ static struct drm_driver sun4i_drv_driver = {
 	.dumb_create		= drm_gem_cma_dumb_create,
 	.dumb_destroy		= drm_gem_dumb_destroy,
 	.dumb_map_offset	= drm_gem_cma_dumb_map_offset,
-	.gem_free_object	= drm_gem_cma_free_object,
+	.gem_free_object_unlocked = drm_gem_cma_free_object,
 	.gem_vm_ops		= &drm_gem_cma_vm_ops,
 
 	/* PRIME Operations */