Fix arc patch adding unnecessary files for hg repos

Summary:
Arc patch was committing with -A (--addremove) which meant any random
files that were sitting around in the repo (like conflict .orig files) were
added to the commit.  The -A isn't even necessary since the hg import
adds and removes all the appropriate files for you.

Test Plan:
touch foo
arc patch --diff some-diff-id
Verified that foo was not added to the commit

Reviewers: epriestley, nh

Reviewed By: epriestley

CC: dschleimer, bos, sid0, aran, Korvin

Differential Revision: https://secure.phabricator.com/D5396

src/workflow/ArcanistPatchWorkflow.php

@@ -773,7 +773,7 @@ EOTEXT
 
         $commit_message = $this->getCommitMessage($bundle);
         $future = $repository_api->execFutureLocal(
-          'commit -A %C -l -',
+          'commit %C -l -',
           $author_cmd);
         $future->write($commit_message);
         $future->resolvex();