Windows: AFSExamineObject() refcnt underflows

Now that the reference counting is likely to be correct, do not
garbage collect objects with negative reference counts.  If the
reference counts are wrong the objects will never be destroyed but
that is now a safer choice than freeing memory that might be in use.

Reviewed-on: http://gerrit.openafs.org/9670
Reviewed-by: Mark Vitale <mvitale@sinenomine.net>
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>
Tested-by: Jeffrey Altman <jaltman@your-file-system.com>
(cherry picked from commit 36fee95e32835cf20286c5225e56b303dd4563da)

Change-Id: Idafa8a58f362cfb082ddaee32715b1ff8550249d
Reviewed-on: http://gerrit.openafs.org/9730
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>
Windows: Protect AFSDeleteObjectInfo calls

Only permit AFSDeleteObjectInfo() to be called if the reference
count returned by AFSObjectInfoDecrement() is zero.

Reviewed-on: http://gerrit.openafs.org/9671
Reviewed-by: Mark Vitale <mvitale@sinenomine.net>
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>
Tested-by: Jeffrey Altman <jaltman@your-file-system.com>
(cherry picked from commit 7252f3125da093a1f9de5ef7ded470ddad12eb9d)

Change-Id: Id099faf08ebd9d51a82b8903840b32950c32b159
Reviewed-on: http://gerrit.openafs.org/9731
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>