ipv6: Use universal hash for NDISC.

In order to perform a proper universal hash on a vector of integers,
we have to use different universal hashes on each vector element.

Which means we need 4 different hash randoms for ipv6.

Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/arp.h b/include/net/arp.h
index 4979af8..0013dc8 100644
--- a/include/net/arp.h
+++ b/include/net/arp.h
@@ -23,7 +23,7 @@
 
 	rcu_read_lock_bh();
 	nht = rcu_dereference_bh(tbl->nht);
-	hash_val = arp_hashfn(key, dev, nht->hash_rnd) >> (32 - nht->hash_shift);
+	hash_val = arp_hashfn(key, dev, nht->hash_rnd[0]) >> (32 - nht->hash_shift);
 	for (n = rcu_dereference_bh(nht->hash_buckets[hash_val]);
 	     n != NULL;
 	     n = rcu_dereference_bh(n->next)) {