Use wxString::t_str() in calls to Windows API functions in wxMSW.

Use t_str() instead of wx_str() to make the code work correctly in UTF-8 build
in which wx_str() returns a pointer to UTF-8 buffer while we need a wchar_t
pointer for Windows.

Closes #14371.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@71640 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/msw/fontenum.cpp

@@ -160,7 +160,7 @@ void wxFontEnumeratorHelper::DoEnumerate()
 
 #ifdef __WXWINCE__
     ::EnumFontFamilies(hDC,
-                       m_facename.empty() ? NULL : m_facename.wx_str(),
+                       m_facename.empty() ? NULL : wxMSW_CONV_LPCTSTR(m_facename),
                        (wxFONTENUMPROC)wxFontEnumeratorProc,
                        (LPARAM)this) ;
 #else // __WIN32__