corrected warnings when compiling with -Wall -W

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@15348 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/mac/metafile.h

@@ -51,7 +51,8 @@ class WXDLLEXPORT wxMetafile: public wxGDIObject
   DECLARE_DYNAMIC_CLASS(wxMetafile)
  public:
   // Copy constructor
-  inline wxMetafile(const wxMetafile& metafile)
+  wxMetafile(const wxMetafile& metafile)
+      : wxGDIObject()
   { Ref(metafile); }
 
   wxMetafile(const wxString& file = "");