Windows: Use AFS_OBJECT_REFERENCE_MAX in struct

Use AFS_OBJECT_REFERENCE_MAX to size the array in the struct.
This should have been a part of patchset
e267774f1a4f9cc5bfc32c545df36a4bf7947607.

Reviewed-on: http://gerrit.openafs.org/9066
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>
(cherry picked from commit 52cc7988371ead9b2903d90453598b3d07ce1696)

Change-Id: I11a26c41f630cc0a304f55b94c9f7fbda4d1a6b6
Reviewed-on: http://gerrit.openafs.org/9102
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>