#3 daemon should exit with status 0 when recieving signals TERM, QUIT or INT

[genodeftest]

Rationale:
I noticed that systemd (systemctl status rcpbind) reports haveged to
have failed every time systemd tries to stop rcpbind. The reason is:
rcpbind exits with exit(2) even when exiting successfully after
receiving SIGTERM/SIGQUIT/SIGINT.

I think rcpbind should exit with exit(0) from rcpbind.c:terminate(733) i.e.
when exiting because of a recieved signal.