Fix a broken method call

Summary: The method is actually named DivinerAtomRef::newFromDictionary.

Test Plan: ./bin/diviner generate --publisher DivinerStaticPublisher worked a bit better.

Reviewers: #blessed_reviewers, epriestley

Reviewed By: #blessed_reviewers, epriestley

Subscribers: Korvin, epriestley

Differential Revision: https://secure.phabricator.com/D11590