netfilter: nf_tables: reduce trans->ctx.chain references

These objects are the trans_chain subtype, so use the helper instead
of referencing trans->ctx, which will be removed soon.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

net/netfilter/nf_tables_api.c

@@ -1262,7 +1262,7 @@ static bool nft_table_pending_update(const struct nft_ctx *ctx)
 		    ((trans->msg_type == NFT_MSG_NEWCHAIN &&
 		      nft_trans_chain_update(trans)) ||
 		     (trans->msg_type == NFT_MSG_DELCHAIN &&
-		      nft_is_base_chain(trans->ctx.chain))))
+		      nft_is_base_chain(nft_trans_chain(trans)))))
 			return true;
 	}
 
@@ -2815,13 +2815,11 @@ static struct nft_chain *nft_chain_lookup_byid(const struct net *net,
 	struct nft_trans *trans;
 
 	list_for_each_entry(trans, &nft_net->commit_list, list) {
-		struct nft_chain *chain = trans->ctx.chain;
-
 		if (trans->msg_type == NFT_MSG_NEWCHAIN &&
-		    chain->table == table &&
+		    nft_trans_chain(trans)->table == table &&
 		    id == nft_trans_chain_id(trans) &&
-		    nft_active_genmask(chain, genmask))
-			return chain;
+		    nft_active_genmask(nft_trans_chain(trans), genmask))
+			return nft_trans_chain(trans);
 	}
 	return ERR_PTR(-ENOENT);
 }
@@ -10625,9 +10623,9 @@ static int __nf_tables_abort(struct net *net, enum nfnl_abort_action action)
 					break;
 				}
 				nft_use_dec_restore(&table->use);
-				nft_chain_del(trans->ctx.chain);
+				nft_chain_del(nft_trans_chain(trans));
 				nf_tables_unregister_hook(trans->ctx.net, table,
-							  trans->ctx.chain);
+							  nft_trans_chain(trans));
 			}
 			break;
 		case NFT_MSG_DELCHAIN:
@@ -10637,7 +10635,7 @@ static int __nf_tables_abort(struct net *net, enum nfnl_abort_action action)
 					    &nft_trans_basechain(trans)->hook_list);
 			} else {
 				nft_use_inc_restore(&table->use);
-				nft_clear(trans->ctx.net, trans->ctx.chain);
+				nft_clear(trans->ctx.net, nft_trans_chain(trans));
 			}
 			nft_trans_destroy(trans);
 			break;