Reduce Lint/Unit rendering duplication

Summary: Ref T8096. No functional changes, just a bit less code.

Test Plan: Viewed some revisions, saw the same stuff as before.

Reviewers: btrahan

Reviewed By: btrahan

Subscribers: epriestley

Maniphest Tasks: T8096

Differential Revision: https://secure.phabricator.com/D13404