R1:b6e0ca5ac6f4

Prevent audit email from sending as the wrong user

Summary: We may overwrite $comment as a side effect of iteration.

Test Plan: Made some audit comments as different users.

Reviewers: vrana, btrahan

Reviewed By: vrana

CC: aran, epriestley

Differential Revision: https://secure.phabricator.com/D2050