doc: name the supported log levels for ipt_LOG

Leonardo Ferreira da Silva Boiko lets it be known that syslogd.conf may
not exist on certain systems. Referencing that manpage is not a good
idea in any case, I believe, since the strings that are accepted are
defined by iptables and not a syslog implementation.

References: http://bugs.debian.org/567564
Signed-off-by: Jan Engelhardt <jengelh@inai.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2 files changed