Fix build of user-space on nbsd50 and greater

Fix build of user-space on nbsd50 and greater

Reviewed-on: http://gerrit.openafs.org/4509
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Tested-by: Jonathan A. Kollasch <jakllsch@kollasch.net>
Reviewed-by: Derrick Brashear <shadow@dementia.org>
(cherry picked from commit da3ee813960d90ea83851c47fbd59eb3012c7904)

Change-Id: If5d8b7e2edd3a8b6ff3cec97800900011fb6ea90
Reviewed-on: http://gerrit.openafs.org/5423
Reviewed-by: Derrick Brashear <shadow@dementix.org>
Tested-by: Derrick Brashear <shadow@dementix.org>