Fix IPV6 DAD handling

commit 9e3be4b3 in mainline

addrconf_dad_failure calls addrconf_dad_stop which takes referenced address
and drops the count. So, in6_ifa_put perrformed at out: is extra. This
results in message: "Freeing alive inet6 address" and not released dst entries.
Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: Alexey Dobriyan <adobriyan@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

net/ipv6/ndisc.c

@@ -736,7 +736,7 @@ static void ndisc_recv_ns(struct sk_buff *skb)
 				 * so fail our DAD process
 				 */
 				addrconf_dad_failure(ifp);
-				goto out;
+				return;
 			} else {
 				/*
 				 * This is not a dad solicitation.