Minor, fix a fatal on Herald Admin controller

Summary:
Just a bad merge for the edit history, I think. We need to pass $user or we
fatal trying to render timestamps.

https://secure.phabricator.com/herald/all/view/differential/

Test Plan: Looked at Herald admin view.

Reviewers: jungejason, xela, nh, btrahan, fratrik

Reviewed By: fratrik

CC: aran, epriestley

Differential Revision: https://secure.phabricator.com/D1611