[IPV6]: Don't dump temporary addresses twice

Each IPv6 Temporary Address (w/ CONFIG_IPV6_PRIVACY) is dumped twice
to netlink.

Because temporary addresses are listed in idev->addr_list,
there's no need to dump idev->tempaddr separately.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>