ipv6: fix typo in fib6_net_exit()

IPv6 FIB should use FIB6_TABLE_HASHSZ, not FIB_TABLE_HASHSZ.

Fixes: ba1cc08d9488 ("ipv6: fix memory leak with multiple tables during netns destruction")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv6/ip6_fib.c

@@ -2033,7 +2033,7 @@ static void fib6_net_exit(struct net *net)
 	rt6_ifdown(net, NULL);
 	del_timer_sync(&net->ipv6.ip6_fib_timer);
 
-	for (i = 0; i < FIB_TABLE_HASHSZ; i++) {
+	for (i = 0; i < FIB6_TABLE_HASHSZ; i++) {
 		struct hlist_head *head = &net->ipv6.fib_table_hash[i];
 		struct hlist_node *tmp;
 		struct fib6_table *tb;