Windows: AFSMarkDirty() require ExtentsResource held
Instead of dynamically testing if the ExtentsResource is held
and if not acquire it within AFSMarkDirty(), simply require that
it be held. AFSMarkDirty() is only called from one location.
Change-Id: If30fc05fead4c9e0604555239e9b862659de3e8b
Reviewed-on: http://gerrit.openafs.org/8304
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>
Tested-by: Jeffrey Altman <jaltman@your-file-system.com>