cleanup: Remove some unhelpful unused variables in destructuring

We aren't using them, and they don't add much in terms of clarity,
so drop them to fix a couple of eslint errors.

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

js/ui/inhibitShortcutsDialog.js

@@ -139,7 +139,7 @@ var InhibitShortcutsDialog = GObject.registerClass({
                         return;
                     }
 
-                    let [permissions, data] = res;
+                    let [permissions] = res;
                     if (permissions[appId] === undefined) // Not found
                         this._dialog.open();
                     else if (permissions[appId] == GRANTED)