Change tricky expression to more formal statement without comma separator

src/animation/KeyframeTrackPrototype.js

@@ -171,7 +171,10 @@ KeyframeTrackPrototype = {
 		if( from !== 0 || to !== nKeys ) {
 
 			// empty tracks are forbidden, so keep at least one keyframe
-			if ( from >= to ) to = Math.max( to , 1 ), from = to - 1;
+			if ( from >= to ){
+				to = Math.max( to , 1 );
+				from = to - 1;
+			}
 
 			var stride = this.getValueSize();
 			this.times = AnimationUtils.arraySlice( times, from, to );