Fix IPV6 DAD handling

Fix IPV6 DAD handling

commit 9e3be4b34364a670bd6e57d2e8c3caabdd8d89f8 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>