Use wxDELETE() and wxDELETEA() when possible.

Use wxDELETE[A]() functions which automatically NULL out their arguments after
deleting them instead of doing it manually.

Closes #9685.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@64656 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/generic/mdig.cpp

@@ -74,11 +74,7 @@ wxGenericMDIParentFrame::~wxGenericMDIParentFrame()
     wxDELETE(m_clientWindow);
 
 #if wxUSE_MENUS
-    if (m_pMyMenuBar)
-    {
-        delete m_pMyMenuBar;
-        m_pMyMenuBar = NULL;
-    }
+    wxDELETE(m_pMyMenuBar);
 
     RemoveWindowMenu(GetMenuBar());
 #endif // wxUSE_MENUS