netfilter: nf_tables: use hook state from xt_action_param structure

Don't copy relevant fields from hook state structure, instead use the
one that is already available in struct xt_action_param.

This patch also adds a set of new wrapper functions to fetch relevant
hook state structure fields.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
diff --git a/net/netfilter/nft_queue.c b/net/netfilter/nft_queue.c
index 393d359..3e19fa1 100644
--- a/net/netfilter/nft_queue.c
+++ b/net/netfilter/nft_queue.c
@@ -43,7 +43,7 @@ static void nft_queue_eval(const struct nft_expr *expr,
 			queue = priv->queuenum + cpu % priv->queues_total;
 		} else {
 			queue = nfqueue_hash(pkt->skb, queue,
-					     priv->queues_total, pkt->pf,
+					     priv->queues_total, nft_pf(pkt),
 					     jhash_initval);
 		}
 	}