Windows: Adjust setting of VERIFY_DATA flag

If the CcPurge operation fails or cannot be performed, in addition
to setting the purge on close flag, set the verify data flag.  This
ensures that the next attempt to access the file will retry the
purge.

Change-Id: I9ebbdab8b5dd31ace5d316454b6e54cf537686d5
Reviewed-on: http://gerrit.openafs.org/10217
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>
Windows: Do not leak activeRPC count

If a callback race has been lost cm_MergeStatus is not executed.
In that case either the activeRPC count should not be incremented
or must be decremented to indicate that the current call has been
completed.

Change-Id: I417f72bbc482f6d207ed0c09770b1d8a53d078ff
Reviewed-on: http://gerrit.openafs.org/10218
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>