pthreadpool: Rearrange locks a bit
Coverity ID
1373624 says we have a deadlock between pthreadpool_prepare and
pthreadpool_destroy. Coverity somehow misses that pthreadpool_free unlocks
pool->mutex, so I think this is a false positive. Nevertheless this re-arranges
the code a bit for more clarity, hoping that Coverity now can better track the
locks and unlocks. Also, the human reader might have to jump between routines a
bit less.
Signed-off-by: Volker Lendecke <vl@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>