use wxString, not wxChar*, in wxDataFormat ctor and SetId() method

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@46254 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/motif/dataform.h

@@ -21,7 +21,6 @@ public:
     wxDataFormat();
     wxDataFormat( wxDataFormatId type );
     wxDataFormat( const wxString &id );
-    wxDataFormat( const wxChar *id );
     wxDataFormat( NativeFormat format );
 
     wxDataFormat& operator=(NativeFormat format)
@@ -48,7 +47,7 @@ public:
     // string ids are used for custom types - this SetId() must be used for
     // application-specific formats
     wxString GetId() const;
-    void SetId( const wxChar *id );
+    void SetId( const wxString& id );
 
     // implementation
     wxDataFormatId GetType() const;