use Core::Id for IEditorFactory::id

Change-Id: Iefd67a0461d9016b8ba0f3371df7ec6d42e188c5
Reviewed-on: http://codereview.qt-project.org/4321
Reviewed-by: hjk <qthjk@ovi.com>

src/plugins/qmljseditor/qmljseditorfactory.cpp

@@ -95,13 +95,9 @@ QmlJSEditorFactory::QmlJSEditorFactory(QObject *parent)
             ;
 }
 
-QmlJSEditorFactory::~QmlJSEditorFactory()
+Core::Id QmlJSEditorFactory::id() const
 {
-}
-
-QString QmlJSEditorFactory::id() const
-{
-    return QLatin1String(C_QMLJSEDITOR_ID);
+    return C_QMLJSEDITOR_ID;
 }
 
 QString QmlJSEditorFactory::displayName() const