editormanager: simplify use of interface

Less code on the user side, same meaning.

Change-Id: I14e54a5d2ed8e024a51cce74eaf7c8419ad544be
Reviewed-by: Eike Ziller <eike.ziller@nokia.com>

src/plugins/classview/classviewmanager.cpp

@@ -309,8 +309,7 @@ void Manager::gotoLocations(const QList<QVariant> &list)
     bool currentPositionAvailable = false;
 
     // what is open now?
-    Core::IEditor *editor = Core::EditorManager::instance()->currentEditor();
-    if (editor) {
+    if (Core::IEditor *editor = Core::EditorManager::currentEditor()) {
         // get current file name
         Core::IDocument *document = editor->document();
         if (document)