Remove UKERNEL code from files that don't need it

Remove #ifdef UKERNEL sections from auth, kauth, ptserver, and ubik sources
that are no longer part of libuafs

Change-Id: I515f65c7e634d9562680c60666a15758261aaae0
Reviewed-on: http://gerrit.openafs.org/9955
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>