OpenBSD: Don't call non-existent routines in osi_vfsops.c

OpenBSD: Don't call non-existent routines in osi_vfsops.c

The OpenBSD version of osi_vfsops.c makes calls to routines
that do not exist in the system and aren't needed. In the
past, these calls were wrappered by an #ifdef for
AFS_DISCON_ENV which was never defined. That #ifdef is now
gone so this patch removes the calls to these routines,
which are remnants of the NBSD origins for this particular
code.

Change-Id: I8cc97fde8cd5cf6c241dd3074c0f97b5d3e2ccfd
Reviewed-on: http://gerrit.openafs.org/3686
Reviewed-by: Derrick Brashear <shadow@dementia.org>
Tested-by: BuildBot <buildbot@rampaginggeek.com>