Fix a possible fatal on the first push to a cluster repository

Summary:
Fixes T11020. I think this resolves things -- `$new_version` (set above) should be used, not `$new_log` directly.

Specifically, we would get into trouble if the initial push failed for some reason (working copy not initialized yet, commit hook rejected, etc).

Test Plan: Made a bad push to a new repository. Saw it freeze before the patch and succeed afterwards.

Reviewers: chad

Reviewed By: chad

Maniphest Tasks: T11020

Differential Revision: https://secure.phabricator.com/D15969

Author: epriestley

src/applications/diffusion/protocol/DiffusionRepositoryClusterEngine.php

@@ -391,7 +391,7 @@ public function synchronizeWorkingCopyAfterWrite() {
           $repository_phid,
           $device_phid,
           $this->clusterWriteVersion,
-          $new_log->getID(),
+          $new_version,
           $this->clusterWriteOwner);
         $did_release = true;
         break;