Windows: AFSNotifyHardLink() DirOpenReferenceCount handling

This patchset consolidates the releasing of the DirOpenReferenceCount
within AFSNotifyHardLink() into the try_exit block.  This clarifies
the logic and avoids duplicate code blocks.

Change-Id: I7bf7e5af55646ea570c76e36a673900521a3582c
Reviewed-on: http://gerrit.openafs.org/8856
Reviewed-by: Derrick Brashear <shadow@your-file-system.com>
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>
Tested-by: Jeffrey Altman <jaltman@your-file-system.com>