cleanup: Only omit braces for single-line blocks

Braces can be avoided when a block consists of a single statement,
but readability suffers when the statement spans more than a single
line.

https://gitlab.gnome.org/GNOME/gnome-shell/merge_requests/805

js/ui/overviewControls.js

@@ -13,10 +13,10 @@ var SIDE_CONTROLS_ANIMATION_TIME = 160;
 
 function getRtlSlideDirection(direction, actor) {
     let rtl = (actor.text_direction == Clutter.TextDirection.RTL);
-    if (rtl)
+    if (rtl) {
         direction = (direction == SlideDirection.LEFT)
             ? SlideDirection.RIGHT : SlideDirection.LEFT;
-
+    }
     return direction;
 }