Fix audit commenting where there are only inlines

Summary: been some changes here and this code was broked. turns out we re-assign $action like two lines later and never used the initial value, so we can simply delete the offending line. Fixes T5745.

Test Plan: submitted inline comment pre-patch and fatal. re-submitted post patch and great success!

Reviewers: epriestley

Reviewed By: epriestley

Subscribers: epriestley, Korvin

Maniphest Tasks: T5745

Differential Revision: https://secure.phabricator.com/D10078

src/applications/audit/editor/PhabricatorAuditCommentEditor.php

@@ -74,8 +74,6 @@ final class PhabricatorAuditCommentEditor extends PhabricatorEditor {
         'commitPHID = %s',
         $commit->getPHID());
 
-    $action = $comment->getAction();
-
     // TODO: We should validate the action, currently we allow anyone to, e.g.,
     // close an audit if they muck with form parameters. I'll followup with this
     // and handle the no-effect cases (e.g., closing and already-closed audit).