[IPV6]: Fix refcounting for anycast dst entries.

The problem occures when we stop IPv6 device without dropping all addresses
on it. For such a device addrconf_ifdown marks all entries as obsolete and
ip6_del_rt called from __ipv6_dev_ac_dec return ENOENT.
The referrence is not dropped.

The fix is simple. DST entry should not keep referrence when stored in the
FIB6 tree.

Signed-off-by: Denis V. Lunev <den@openvz.org>
--- ./net/ipv6/anycast.c.ac1	2008-03-17 17:29:55.000000000 +0300
+++ ./net/ipv6/anycast.c	2008-03-18 11:16:23.000000000 +0300
@@ -347,9 +347,7 @@ int ipv6_dev_ac_inc(struct net_device *d
 	idev->ac_list = aca;
 	write_unlock_bh(&idev->lock);
 
-	dst_hold(&rt->u.dst);
-	if (ip6_ins_rt(rt, NULL, NULL, NULL))
-		dst_release(&rt->u.dst);
+	ip6_ins_rt(rt, NULL, NULL, NULL);
 
 	addrconf_join_solict(dev, &aca->aca_addr);
 
@@ -394,10 +392,7 @@ int __ipv6_dev_ac_dec(struct inet6_dev *
 	addrconf_leave_solict(idev, &aca->aca_addr);
 
 	dst_hold(&aca->aca_rt->u.dst);
-	if (ip6_del_rt(aca->aca_rt, NULL, NULL, NULL))
-		dst_free(&aca->aca_rt->u.dst);
-	else
-		dst_release(&aca->aca_rt->u.dst);
+	ip6_del_rt(aca->aca_rt, NULL, NULL, NULL);
 
 	aca_put(aca);
 	return 0;