Hygiene: fix feedback from scrutinizer

I ran scrutinizer-ci.com against flow - these are some of the things it came up
with.

https://scrutinizer-ci.com/g/matthiasmullie/mediawiki-extensions-Flow/inspections/d37be56d-1a25-4c3c-8f2e-f47fc8f3c403/patches

Change-Id: I73d9314cc40387dfcfb0600b339bff6f25c1d75d