animation: fix move scale animation

Both weston_move_scale_run() and weston_slide_run() were broken in
commit 3a869019. Commit a4a6f161 fixed and explained the problem for
weston_slide_run() but weston_move_scale_run() remained broken.

To fix weston_move_scale_run(), weston_view_animation_run() is also
required. It was removed when _run() was split into two functions
_create() and _run() in commit f5cc2b56, but _run() was not added in
this commit.

src/animation.c

@@ -458,8 +458,10 @@ weston_move_scale_run(struct weston_view *view, int dx, int dy,
 	if (animation == NULL)
 		return NULL;
 
-	weston_spring_init(&animation->spring, 400.0, start, end);
+	weston_spring_init(&animation->spring, 400.0, 0.0, 1.0);
 	animation->spring.friction = 1150;
 
+	weston_view_animation_run(animation);
+
 	return animation;
 }