QWidget: Answer question raised in fixme comment

Add a comment for fixme comment added in
f1268d137e.

Change-Id: I08cd104442b13925be2aa5a48e64e391c9903099
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>

src/widgets/kernel/qwidget.cpp

@@ -7669,7 +7669,7 @@ void QWidget::show()
     else if (defaultState == Qt::WindowMaximized)
         showMaximized();
     else
-        setVisible(true); // FIXME: Why not showNormal(), like QWindow::show()?
+        setVisible(true); // Don't call showNormal() as not to clobber Qt::Window(Max/Min)imized
 }
 
 /*! \internal