Fix passing a TString into printf.

git-svn-id: http://root.cern.ch/svn/root/trunk@23915 27541ba8-7e3a-0410-8455-c3a389f83636

graf3d/eve/src/TEveTrackEditor.cxx

@@ -483,7 +483,8 @@ void TEveTrackCounterEditor::DoFileReport()
       fM->OutputEventTracks(out);
       fclose(out);
    } else {
-      Error("TEveTrackCounterEditor::DoFileReport", "Can not open file '%s' for writing.", file);
+      Error("TEveTrackCounterEditor::DoFileReport",
+            "Can not open file '%s' for writing.", file.Data());
    }
 }