Correctly calculate "any_failed"

Summary: See T10746.

Test Plan: Fail one of several builds, run ./bin/harbormaster update, see that Build Status is Failed.

Reviewers: #blessed_reviewers, epriestley

Reviewed By: #blessed_reviewers, epriestley

Subscribers: epriestley, O14 ATC Monitoring, yelirekim

Maniphest Tasks: T10746

Differential Revision: https://secure.phabricator.com/D16480