netfilter: nf_tables: add single table list for all families

Place all existing user defined tables in struct net *, instead of
having one list per family. This saves us from one level of indentation
in netlink dump functions.

Place pointer to struct nft_af_info in struct nft_table temporarily, as
we still need this to put back reference module reference counter on
table removal.

This patch comes in preparation for the removal of struct nft_af_info.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
diff --git a/net/netfilter/nft_redir.c b/net/netfilter/nft_redir.c
index 1e66538..c64cbe7 100644
--- a/net/netfilter/nft_redir.c
+++ b/net/netfilter/nft_redir.c
@@ -75,7 +75,7 @@ int nft_redir_init(const struct nft_ctx *ctx,
 			return -EINVAL;
 	}
 
-	return nf_ct_netns_get(ctx->net, ctx->afi->family);
+	return nf_ct_netns_get(ctx->net, ctx->family);
 }
 EXPORT_SYMBOL_GPL(nft_redir_init);