genetlink: optimize ctrl_dumpfamily()

there is a unnecessary test which can be replaced by a good initialization in
the 'for' statement

Noticed by Serge E. Hallyn <serue@us.ibm.com>

Signed-off-by: Samir Bellabes <sam@synack.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/netlink/genetlink.c

@@ -681,9 +681,7 @@ static int ctrl_dumpfamily(struct sk_buff *skb, struct netlink_callback *cb)
 	int chains_to_skip = cb->args[0];
 	int fams_to_skip = cb->args[1];
 
-	for (i = 0; i < GENL_FAM_TAB_SIZE; i++) {
-		if (i < chains_to_skip)
-			continue;
+	for (i = chains_to_skip; i < GENL_FAM_TAB_SIZE; i++) {
 		n = 0;
 		list_for_each_entry(rt, genl_family_chain(i), family_list) {
 			if (!rt->netnsok && !net_eq(net, &init_net))