cleanup: Avoid useless return statements

Return statements are only useful if they return a value or break
the regular function flow (i.e. early returns). Remove all returns
that do neither.

https://gitlab.gnome.org/GNOME/gnome-shell/merge_requests/731

js/ui/main.js

@@ -705,7 +705,6 @@ function queueDeferredWork(workId) {
         _deferredWorkQueue.push(workId);
     if (data.actor.mapped) {
         _queueBeforeRedraw(workId);
-        return;
     } else if (_deferredTimeoutId == 0) {
         _deferredTimeoutId = GLib.timeout_add_seconds(GLib.PRIORITY_DEFAULT, DEFERRED_TIMEOUT_SECONDS, () => {
             _runAllDeferredWork();