Windows: cm_user interlocked operations

Convert cm_user refcnts to use interlocked operations.

Reviewed-on: http://gerrit.openafs.org/9061
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 e4d97fa3e4a0d02160e082547b84c437472bfaae)

Change-Id: I5dc693021772055cd7e232ec27122b867de7691d
Reviewed-on: http://gerrit.openafs.org/9063
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>
Windows: cm_SetupFetchBIOD reserving type

Change type of 'reserving' to afs_uint64 to match the return type
of buf_TryReserveBuffers().

Reviewed-on: http://gerrit.openafs.org/9062
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 4b3f499b20ba50cf92e6caeb747c56e53a5a55f3)

Change-Id: Id3eedda4acca2bdc69136c995efb0aefc2d1174f
Reviewed-on: http://gerrit.openafs.org/9064
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>