Windows: Avoid deadlock during pending delete cleanup

Release the Fcb resource and clear the AFS_DIR_ENTRY_PENDING_DELETE
flag prior to the AFSProcessRequest(AFS_REQUEST_TYPE_CLEANUP_PROCESSING)
if a delete is pending during cleanup of the last FCB open handle.

Failure to do so results in an out of order lock acquisition when
the parent object info tree lock is acquired after the AFSProcessRequest()
call to the service completes.

Reviewed-on: http://gerrit.openafs.org/11425
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>
(cherry picked from commit 58e4e4802d4208604a6aa05362454e6174fe3277)

Change-Id: Ic4565afc6e356f33ddb6290c5399656d35a102d5
Reviewed-on: http://gerrit.openafs.org/11428
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>