drm: delay vblank cleanup until after driver unload

Drivers may use vblank calls now (e.g. drm_vblank_off) in their unload
paths, so don't clean up the vblank related structures until after
driver unload.

Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: Kristian Høgsberg <krh@bitplanet.net>
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/drm_stub.c

@@ -515,8 +515,6 @@ void drm_put_dev(struct drm_device *dev)
 	}
 	driver = dev->driver;
 
-	drm_vblank_cleanup(dev);
-
 	drm_lastclose(dev);
 
 	if (drm_core_has_MTRR(dev) && drm_core_has_AGP(dev) &&
@@ -536,6 +534,8 @@ void drm_put_dev(struct drm_device *dev)
 		dev->agp = NULL;
 	}
 
+	drm_vblank_cleanup(dev);
+
 	list_for_each_entry_safe(r_list, list_temp, &dev->maplist, head)
 		drm_rmmap(dev, r_list->map);
 	drm_ht_remove(&dev->map_hash);