Use scoped names in revision query

Test Plan:

id(new DifferentialRevisionQuery())
  ->withIDs($revision_ids)
  ->withDraftRepliesByAuthors($user_phids)
  ->execute();

Reviewers: epriestley

Reviewed By: epriestley

CC: aran, Korvin

Differential Revision: https://secure.phabricator.com/D3322