Stop spamming the logs with "Could not remove pid XX from serverid.tdb" messages...

Stop spamming the logs with "Could not remove pid XX from serverid.tdb" messages and initiating the cleanup function on every process death.

We now have many sub-processes from smbd that don't serve SMB1/SMB2 requests and
don't register themselves in the serverid.tdb. Only initiate the cleanup
from processes that were explicitly in the child list.

Autobuild-User: Jeremy Allison <jra@samba.org>
Autobuild-Date: Thu May 31 04:44:09 CEST 2012 on sn-devel-104