We added check_drive to the account/container servers to unify how all
the storage wsgi servers treat device dirs/mounts. Thus pushes that
unification down into the consistency engine.
Drive-by:
* use FakeLogger less
* clean up some repeititon in probe utility for device re-"mounting"
Related-Change-Id: I3362a6ebff423016bb367b4b6b322bb41ae08764
Change-Id: I941ffbc568ebfa5964d49964dc20c382a5e2ec2a