netfilter: nf_tables: replace unnecessary use of list_for_each_entry_continue()

Since there is no way for list_for_each_entry_continue() to start
interating in the middle of the list they can be replaced with a call
to list_for_each_entry().

In preparation to limit the scope of the list iterator to the list
traversal loop, the list iterator variable 'rule' should not be used
past the loop.

v1->v2:
- also replace first usage of list_for_each_entry_continue() (Florian
Westphal)
Signed-off-by: Jakob Koschel <jakobkoschel@gmail.com>
Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

net/netfilter/nf_tables_api.c

@@ -8367,10 +8367,8 @@ static int nf_tables_commit_chain_prepare(struct net *net, struct nft_chain *cha
 	if (chain->blob_next || !nft_is_active_next(net, chain))
 		return 0;
 
-	rule = list_entry(&chain->rules, struct nft_rule, list);
-
 	data_size = 0;
-	list_for_each_entry_continue(rule, &chain->rules, list) {
+	list_for_each_entry(rule, &chain->rules, list) {
 		if (nft_is_active_next(net, rule)) {
 			data_size += sizeof(*prule) + rule->dlen;
 			if (data_size > INT_MAX)
@@ -8387,7 +8385,7 @@ static int nf_tables_commit_chain_prepare(struct net *net, struct nft_chain *cha
 	data_boundary = data + data_size;
 	size = 0;
 
-	list_for_each_entry_continue(rule, &chain->rules, list) {
+	list_for_each_entry(rule, &chain->rules, list) {
 		if (!nft_is_active_next(net, rule))
 			continue;