CppEditor: Fix build with namespaced Qt.

Change-Id: Id5a2dce79b27c8c4599d7cdc0935064f5db44f13
Reviewed-by: Christian Kandeler <christian.kandeler@digia.com>

src/plugins/cppeditor/cpppreprocessoradditionwidget.h

@@ -37,12 +37,9 @@
 #include <QVariantMap>
 #include <QPointer>
 
-namespace Ui {
-class CppPreProcessorAdditionWidget;
-}
-
 namespace CppEditor {
 namespace Internal {
+namespace Ui { class CppPreProcessorAdditionWidget; }
 
 class PreProcessorAdditionWidget : public QWidget
 {

src/plugins/cppeditor/cpppreprocessoradditionwidget.ui

 <?xml version="1.0" encoding="UTF-8"?>
 <ui version="4.0">
- <class>CppPreProcessorAdditionWidget</class>
- <widget class="QWidget" name="CppPreProcessorAdditionWidget">
+ <class>CppEditor::Internal::CppPreProcessorAdditionWidget</class>
+ <widget class="QWidget" name="CppEditor::Internal::CppPreProcessorAdditionWidget">
   <property name="geometry">
    <rect>
     <x>0</x>