ubik: death to orphaned signals

ubik: death to orphaned signals

ubik has a few very old "orphaned" LWP events that are signalled via
LWP_NoYieldSignal, but have no matching waits (LWP_WaitProcess).

Each "signal" runs the LWP waiting element list for each LWP on the
blocked queue; this may add up to substantial wasted overhead on a
heavily loaded ubik server.

Remove the orphaned signals.

No functional difference should be incurred by this commit.

Reviewed-on: https://gerrit.openafs.org/12620
Reviewed-by: Andrew Deason <adeason@sinenomine.net>
Reviewed-by: Michael Meffie <mmeffie@sinenomine.net>
Reviewed-by: Marcio Brito Barbosa <mbarbosa@sinenomine.net>
Reviewed-by: Mark Vitale <mvitale@sinenomine.net>
Tested-by: Andrew Deason <adeason@sinenomine.net>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
(cherry picked from commit e4c7321560acf0bd34eeee7d46269818d82fdb44)

Change-Id: I4303542683aaa62895b73a5ea93bc3d0ac82804a
Reviewed-on: https://gerrit.openafs.org/13123
Reviewed-by: Michael Meffie <mmeffie@sinenomine.net>
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>