MetaCursorRenderer: Rely on update_cursor for redrawing

Calling queue_redraw() in _force_update() is not needed because
update_cursor() will do this when needed, i.e. when switching between
hardware cursor and texture cursor, or when drawing with texture cursor.

There is also no need to force _native_force_update() because
update_cursor() will cover this as well when needed. When not changing
cursor but only the gbm_bo, the "dirty" boolean on the gbm_bo will
trigger a redraw.

https://bugzilla.gnome.org/show_bug.cgi?id=744932

src/backends/native/meta-cursor-renderer-native.c

@@ -305,7 +305,6 @@ meta_cursor_renderer_native_update_animation (MetaCursorRendererNative *native)
   priv->animation_timeout_id = 0;
   meta_cursor_sprite_tick_frame (cursor_sprite);
   meta_cursor_renderer_force_update (renderer);
-  meta_cursor_renderer_native_force_update (native);
 
   return G_SOURCE_REMOVE;
 }