searchDisplay: Remove doSearch

This is nothing but a middle man, as the view selector already owns
the search system. We want to start being a bit more tricky with what
we do with the search system so that we ignore whitespace, so let's
cut the middle-man out now.

https://bugzilla.gnome.org/show_bug.cgi?id=693458

js/ui/viewSelector.js

@@ -423,7 +423,7 @@ const ViewSelector = new Lang.Class({
 
     _doSearch: function () {
         this._searchTimeoutId = 0;
-        this._searchResults.doSearch(this._text.text);
+        this._searchSystem.updateSearch(this._text.text);
 
         this._showPage(this._searchPage);
     },