viced: Rename fs_rxstat_userok

The fs_rxstat_userok function can be used for other purposes; give it
a more general name.

Reviewed-on: http://gerrit.openafs.org/7571
Reviewed-by: Derrick Brashear <shadow@dementix.org>
Tested-by: BuildBot <buildbot@rampaginggeek.com>
(cherry picked from commit 7a875f639f61966f2d327f929305091d2678e99a)

Change-Id: I44301904cc8e7145ba13276a32b7cea475bc0574
Reviewed-on: http://gerrit.openafs.org/9484
Reviewed-by: Andrew Deason <adeason@sinenomine.net>
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Derrick Brashear <shadow@your-file-system.com>