extensions: AUDIT: fix man-page typo.

A recent commit fixed uses of "allows to" in man-pages.  There was one
instance where the "to" was removed but the "allows" was left behind.
Remove that as well.

Fixes: 3b9b515618c6 ("iptables: cleanup "allows to" usage")
Signed-off-by: Jeremy Sowden <jeremy@azazel.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>