nft: consolidate nft_rule_* functions to support ARP

This should help to avoid code duplication to support ARP.
As a result, we have a common generic infrastructure for
IPv4, IPv6 and ARP.

This patch removes nft_arp_rule_append and nft_arp_rule_insert,
which were very similar to their original nft_rule_append and
nft_rule_insert.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
3 files changed