Rename IDocument::fileName --> filePath

That is what it actually is, wrt how Qt API calls it.

Change-Id: Ied02055debf6aad75556b0d9d22e8ba2f72be555
Reviewed-by: Eike Ziller <eike.ziller@digia.com>

src/plugins/coreplugin/dialogs/saveitemsdialog.cpp

@@ -62,7 +62,7 @@ SaveItemsDialog::SaveItemsDialog(QWidget *parent,
     foreach (IDocument *document, items) {
         QString visibleName;
         QString directory;
-        QString fileName = document->fileName();
+        QString fileName = document->filePath();
         if (fileName.isEmpty()) {
             visibleName = document->suggestedFileName();
         } else {