Windows: AFSDeleteObjectInfo InterlockedExchange

Use InterlockedExchangePointer to disconnect the ObjectInformationCB
pointer from the caller.  This ensures that only one thread can
successfully call AFSDeleteObjectInfo on the same object at a time.

Reviewed-on: http://gerrit.openafs.org/9644
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Peter Scott <pscott@kerneldrivers.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>
Tested-by: Jeffrey Altman <jaltman@your-file-system.com>
(cherry picked from commit ef5ea5120ea0af85d73fa7588dd0efc947a174d9)

Change-Id: Ifd6644acd0051cb4d483933264f4a76ff772d8af
Reviewed-on: http://gerrit.openafs.org/9652
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>
Windows: NPCancelConnection without drive letter

When canceling a network connection to a UNC path, do not match
connections that have drive letters assigned.  Only cancel the connection
if there it matches the UNC path and has no local name.

Reviewed-on: http://gerrit.openafs.org/9640
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Peter Scott <pscott@kerneldrivers.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>
Tested-by: Jeffrey Altman <jaltman@your-file-system.com>
(cherry picked from commit f7cf559480c04989c7c46126f2036fe78f301705)

Change-Id: I5de276acfe2441eb74a6cf1ea1b5e2f2d4a85458
Reviewed-on: http://gerrit.openafs.org/9653
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>