swipe-tracker: Don't animate when the distance is 0

Usually it makes sense to restrict the minimum animation duration. However,
if the progress already matches the end progress, it just causes a delay,
so skip it completely.
Signed-off-by: Alexander Mikhaylenko <alexm@gnome.org>

src/hdy-swipe-tracker.c

@@ -260,7 +260,8 @@ gesture_end (HdySwipeTracker *self)
     velocity = self->velocity;
 
   duration = ABS ((self->progress - end_progress) / velocity * DURATION_MULTIPLIER);
-  duration = CLAMP (duration, MIN_ANIMATION_DURATION, MAX_ANIMATION_DURATION);
+  if (self->progress != end_progress)
+    duration = CLAMP (duration, MIN_ANIMATION_DURATION, MAX_ANIMATION_DURATION);
 
   hdy_swipeable_end_swipe (self->swipeable, duration, end_progress);