Fix a pht method call

Summary: Ref T7046. I missed this in D11680.

Test Plan: arc lint

Reviewers: Blessed Reviewers, epriestley

Reviewed By: Blessed Reviewers, epriestley

Subscribers: Korvin, epriestley

Maniphest Tasks: T7046

Differential Revision: https://secure.phabricator.com/D11731