regsim: enhance kernel workqueue simulation
regsim: enhance kernel workqueue simulation

Given that pthread_cond_wait() will unlock the mutex so
no need to do the nasty shit without locking. This is POSIX
sane. Thanks to Adrian Chadd <adrian@freebsd.org> for his review
and suggestions.

Signed-off-by: Luis R. Rodriguez <d4fa18192c5a479e564d29c2300c2e15afd1d8d7@do-not-panic.com>

mcgrof/regsim,mcgrof/regsim