netfilter: nf_tables: memleak flow rule from commit path

Abort path release flow rule object, however, commit path does not.
Update code to destroy these objects before releasing the transaction.

Fixes: c9626a2c ("netfilter: nf_tables: add hardware offload support")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

net/netfilter/nf_tables_api.c

@@ -8329,6 +8329,9 @@ static void nft_commit_release(struct nft_trans *trans)
 		nf_tables_chain_destroy(&trans->ctx);
 		break;
 	case NFT_MSG_DELRULE:
+		if (trans->ctx.chain->flags & NFT_CHAIN_HW_OFFLOAD)
+			nft_flow_rule_destroy(nft_trans_flow_rule(trans));
+
 		nf_tables_rule_destroy(&trans->ctx, nft_trans_rule(trans));
 		break;
 	case NFT_MSG_DELSET:
@@ -8817,6 +8820,9 @@ static int nf_tables_commit(struct net *net, struct sk_buff *skb)
 			nf_tables_rule_notify(&trans->ctx,
 					      nft_trans_rule(trans),
 					      NFT_MSG_NEWRULE);
+			if (trans->ctx.chain->flags & NFT_CHAIN_HW_OFFLOAD)
+				nft_flow_rule_destroy(nft_trans_flow_rule(trans));
+
 			nft_trans_destroy(trans);
 			break;
 		case NFT_MSG_DELRULE: