containers: fix exit status in netns/netns_netlink.c

In iproute2 whose version is earlier than v2.6.34,
ip command doesn't support tuntap object. This leads
to the case (netns_netlink.c) failure with TFAIL status.
It is not suitable, so fix this case' exit status with
TCONF in the above condition.

Signed-off-by: Xing Gu <gux.fnst@cn.fujitsu.com>
1 file changed