Qt: Always return to windowed when confirming exit

If we don't do this the prompt *may* appear behind the fullscreened window
and thus cause confusion. This happens both with exclusive fullscreen and
borderless fullscreen (e.g. for OpenGL).

Source/Core/DolphinQt2/MainWindow.cpp

@@ -624,13 +624,9 @@ bool MainWindow::RequestStop()
   }
 
   if (!m_render_widget->isFullScreen())
-  {
     m_render_widget_geometry = m_render_widget->saveGeometry();
-  }
-  else if (g_ActiveConfig.ExclusiveFullscreenEnabled())
-  {
+  else
     FullScreen();
-  }
 
   if (SConfig::GetInstance().bConfirmStop)
   {