simplify merge prep
simplify merge prep

Summary: clean up stuff after recent merge refactoring

Reviewed By: nmote

Differential Revision: D14854502

fbshipit-source-id: 7e5bbd6fd46710ae996b227df225847f7da87ca5

nmote/flow,nmote/flow,nmote/flow,nmote/flow,nmote/flow,nmote/flow,nmote/flow