tiny refactor: use checkWarn in a few more places
tiny refactor: use checkWarn in a few more places

n054/weave,weaveworks/weave,bboreham/weave,n054/weave,n054/weave,tomwilkie/weave,rade/weave,aaam/weave,bboreham/weave,n054/weave,weaveworks/weave,tomwilkie/weave,dpw/weave,rade/weave,dpw/weave,paulbellamy/weave,aaam/weave,bboreham/weave,dpw/weave,rade/weave,rade/weave,rade/weave,tomwilkie/weave,bboreham/weave,dpw/weave,aaam/weave,tomwilkie/weave,aaam/weave,bboreham/weave,paulbellamy/weave,dpw/weave,weaveworks/weave,paulbellamy/weave,paulbellamy/weave,tomwilkie/weave,weaveworks/weave,n054/weave,aaam/weave