netfilter: nf_tables: add NFT_CHAIN_POLICY_UNSET and use it

Default policy is defined as a unsigned 8-bit field, do not use a
negative value to leave it unset, use this new NFT_CHAIN_POLICY_UNSET
instead.

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