cleanup: Remove some unhelpful unused arguments

Those unused arguments aren't bugs - unbeknownst to eslint, they all
correspond to valid signal parameters - but they don't contribute
anything to clarity, so just remove them anyway.

https://gitlab.gnome.org/GNOME/gnome-shell/merge_requests/627

js/ui/main.js

@@ -658,7 +658,7 @@ function _queueBeforeRedraw(workId) {
  *
  * Returns: A string work identifier
  */
-function initializeDeferredWork(actor, callback, props) {
+function initializeDeferredWork(actor, callback) {
     // Turn into a string so we can use as an object property
     let workId = `${(++_deferredWorkSequence)}`;
     _deferredWorkData[workId] = { 'actor': actor,