net: fix netlink address dumping in IPv4/IPv6

When a dump is interrupted at the last device in a hash chain and
then continued, "idx" won't get incremented past s_idx, so s_ip_idx
is not reset when moving on to the next device. This means of all
following devices only the last n - s_ip_idx addresses are dumped.

Tested-by: Pawel Staszewski <pstaszewski@itcare.pl>
Signed-off-by: Patrick McHardy <kaber@trash.net>
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 3381b43..7e567ae 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -3610,7 +3610,7 @@
 		hlist_for_each_entry_rcu(dev, node, head, index_hlist) {
 			if (idx < s_idx)
 				goto cont;
-			if (idx > s_idx)
+			if (h > s_h || idx > s_idx)
 				s_ip_idx = 0;
 			ip_idx = 0;
 			if ((idev = __in6_dev_get(dev)) == NULL)