animation.c: Schedule a repaint when the animation is done

Otherwise we don't repaint with the final state of the surface and
we're stuck with the second-to-last frame of the animation until
something else (moving the mouse or such) triggers a redraw.

https://bugs.freedesktop.org/show_bug.cgi?id=70930

src/animation.c

@@ -167,6 +167,7 @@ weston_surface_animation_frame(struct weston_animation *base,
 	weston_spring_update(&animation->spring, msecs);
 
 	if (weston_spring_done(&animation->spring)) {
+		weston_compositor_schedule_repaint(animation->surface->compositor);
 		weston_surface_animation_destroy(animation);
 		return;
 	}