viced: remove old signal handler wrappers

viced: remove old signal handler wrappers

Remove remnants of old lwp thread signal handler wrapper functions from
the fileserver. The lwp softsig handlers required a function which was
passed a void pointer argument and returned a void pointer.  Tidy the
code by removing the unneeded wrappers and use the signal handler
functions directly.

Change-Id: I3d52efe659b03ee9a9484ec7a9d74404f1970278
Reviewed-on: https://gerrit.openafs.org/11921
Reviewed-by: Chas Williams <3chas3@gmail.com>
Reviewed-by: Mark Vitale <mvitale@sinenomine.net>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
Tested-by: BuildBot <buildbot@rampaginggeek.com>