String formatting fixes

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@72136 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/richtext/richtextxml.cpp

@@ -875,7 +875,7 @@ bool wxRichTextXMLHandler::DoSaveFile(wxRichTextBuffer *buffer, wxOutputStream&
 
     wxString s ;
     s.Printf(wxT("<?xml version=\"%s\" encoding=\"%s\"?>\n"),
-             version, fileEncoding);
+             version.c_str(), fileEncoding.c_str());
     OutputString(stream, s);
     OutputString(stream, wxT("<richtext version=\"1.0.0.0\" xmlns=\"http://www.wxwidgets.org\">"));