MFC r335899:

MFC r335899:

auditd(8): register signal handlers interrutibly

auditd_wait_for_events() relies on read(2) being interrupted by signals,
but it registers signal handlers with signal(3), which sets SA_RESTART.
That breaks asynchronous signal handling. It means that signals don't
actually get handled until after an audit(8) trigger is received.
Symptoms include:

* Sending SIGTERM to auditd doesn't kill it right away; you must send
  SIGTERM and then send a trigger with auditon(2).
* Same with SIGHUP
* Zombie child processes don't get reaped until auditd receives a trigger
  sent by auditon. This includes children created by expiring audit trails
  at auditd startup.

Fix by using sigaction(2) instead of signal(3).

Cherry pick https://github.com/openbsm/openbsm/commit/d060887

PR:		229381
Reviewed by:	cem
Obtained from:	OpenBSM
Differential Revision:	https://github.com/openbsm/openbsm/pull/36

git-svn-id: svn://svn.freebsd.org/base/stable/10@337257 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f