doc: clarify DEBUG usage macro

Signed-off-by: Alexey Perevalov <a.perevalov@samsung.com>
Signed-off-by: Pablo Neira Ayuso <pablo@gnumonks.org>
ip6tables: don't print out /128

Similar to how iptables does not print /32 on IPv4 addresses, ip6tables
should not print out /128 on IPv6 addresses.

Signed-off-by: Phil Oester <kernel@linuxace.com>
Signed-off-by: Pablo Neira Ayuso <pablo@soleta.eu>