fix minor remarks w.r.t. style & code organization

@ebirn, @georg-rath: some very minor cleanup for https://github.com/hpcugent/easybuild-framework/pull/949

@ebirn: please merge this into your branch by clicking the shiny green button, to get it included in the open PR (which I want to merge in ASAP to get it included in EasyBuild v1.14.0)