STL build compilation fix (remove useless cast of wxString to const wxChar*)

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@51131 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

samples/dragimag/dragimag.cpp

@@ -385,15 +385,12 @@ bool MyApp::OnInit()
 
     wxString rootName(_T("shape0"));
 
-    int i;
-    for (i = 1; i < 4; i++)
+    for (int i = 1; i < 4; i++)
     {
-        wxString filename;
-        filename.Printf(wxT("%s%d.png"), (const wxChar*)rootName, i);
     /* For some reason under wxX11, the 2nd LoadFile in this loop fails, with
        a BadMatch inside CreateFromImage (inside ConvertToBitmap). This happens even if you copy
        the first file over the second file. */
-        if (image.LoadFile(filename, wxBITMAP_TYPE_PNG))
+        if (image.LoadFile(wxString::Format("%s%d.png", rootName, i), wxBITMAP_TYPE_PNG))
         {
             DragShape* newShape = new DragShape(wxBitmap(image));
             newShape->SetPosition(wxPoint(i*50, i*50));