Hygiene: fix feedback from scrutinizer #4

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/issues/

Change-Id: Icecee81bded92f2b74627a0fbd9d0e245aceccd3