netfilter: convert while loops to for loops

This is to facilitate converting from a singly-linked list to an array
of elements.

Signed-off-by: Aaron Conole <aconole@bytheb.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

net/bridge/br_netfilter_hooks.c

@@ -1008,10 +1008,10 @@ int br_nf_hook_thresh(unsigned int hook, struct net *net,
 	struct nf_hook_state state;
 	int ret;
 
-	elem = rcu_dereference(net->nf.hooks[NFPROTO_BRIDGE][hook]);
-
-	while (elem && (nf_hook_entry_priority(elem) <= NF_BR_PRI_BRNF))
-		elem = rcu_dereference(elem->next);
+	for (elem = rcu_dereference(net->nf.hooks[NFPROTO_BRIDGE][hook]);
+	     elem && nf_hook_entry_priority(elem) <= NF_BR_PRI_BRNF;
+	     elem = rcu_dereference(elem->next))
+		;
 
 	if (!elem)
 		return okfn(net, sk, skb);

net/netfilter/core.c

@@ -107,10 +107,9 @@ int nf_register_net_hook(struct net *net, const struct nf_hook_ops *reg)
 	mutex_lock(&nf_hook_mutex);
 
 	/* Find the spot in the list */
-	while ((p = nf_entry_dereference(*pp)) != NULL) {
+	for (; (p = nf_entry_dereference(*pp)) != NULL; pp = &p->next) {
 		if (reg->priority < nf_hook_entry_priority(p))
 			break;
-		pp = &p->next;
 	}
 	rcu_assign_pointer(entry->next, p);
 	rcu_assign_pointer(*pp, entry);
@@ -137,12 +136,11 @@ void nf_unregister_net_hook(struct net *net, const struct nf_hook_ops *reg)
 		return;
 
 	mutex_lock(&nf_hook_mutex);
-	while ((p = nf_entry_dereference(*pp)) != NULL) {
+	for (; (p = nf_entry_dereference(*pp)) != NULL; pp = &p->next) {
 		if (nf_hook_entry_ops(p) == reg) {
 			rcu_assign_pointer(*pp, p->next);
 			break;
 		}
-		pp = &p->next;
 	}
 	mutex_unlock(&nf_hook_mutex);
 	if (!p) {