Minor linter fixes

Summary:
Fixed various linter issues that were identified with `arc lint --everything`.

- Changed tabs to spaces.
- Removed trailing newlines.
- Added whitespace on either side of binary operator.
- Added newline at EOF.
- Minor spelling fix.
- Removed leading newlines.

Test Plan: N/A

Reviewers: epriestley, #blessed_reviewers

Reviewed By: epriestley

CC: Korvin, epriestley, aran

Differential Revision: https://secure.phabricator.com/D8335