Correct reference to FBEHelper in BatchAPI Exception Handler (#2)

Summary:
This corrects an "Undefined Property" error in the exception handler.

Pull Request resolved: #2

Reviewed By: zlik

Differential Revision: D25455026

Pulled By: xiangminxufsu

fbshipit-source-id: cb3d3f76

Facebook/BusinessExtension/Model/Product/Feed/Method/BatchApi.php

@@ -98,7 +98,7 @@ public function generateProductRequestData($accessToken = null)
                         $exceptions++;
                         // Don't overload the logs, log the first 3 exceptions
                         if ($exceptions <= 3) {
-                            $this->_fbeHelper->logException($e);
+                            $this->fbeHelper->logException($e);
                         }
                         // If it looks like a systemic failure : stop feed generation
                         if ($exceptions > 100) {