Windows: out of date version not in current chunk

Windows: out of date version not in current chunk

In buf_GetNewLocked(), the comparision to decide whether a
cm_buf_t is a member of the current chunk must take the data
version into account.  If the data version is out of date, it
is not part of the current chunk and is an object that can be
safely recycled.

Change-Id: Id8ca0a897a0a65efc1cabbe39107ca210b48bd4e
Reviewed-on: http://gerrit.openafs.org/5734
Reviewed-by: Derrick Brashear <shadow@dementix.org>
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Tested-by: Jeffrey Altman <jaltman@secure-endpoints.com>
Reviewed-by: Jeffrey Altman <jaltman@secure-endpoints.com>