Fix local-clobbering iterators in phabricator/

Summary:
These are the issues identified by the linter in D2052. I don't think any cause bugs, but they are all reasonable errors to raise and the linter correctly
detected that they are suspicious.

Test Plan: Mostly inspection.

Reviewers: vrana, btrahan

Reviewed By: vrana

CC: aran, epriestley

Differential Revision: https://secure.phabricator.com/D2053