no changes, just refactor the code to avoid having the same code for m_textCtrl destruction in 4 places

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@53830 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/msw/listctrl.h

@@ -446,6 +446,9 @@ private:
     // UpdateStyle()), only should be called if InReportView()
     void MSWSetExListStyles();
 
+    // destroy m_textCtrl if it's currently valid and reset it to NULL
+    void DeleteEditControl();
+
 
     DECLARE_DYNAMIC_CLASS(wxListCtrl)
     DECLARE_EVENT_TABLE()