ip netns: Fix rtnl error while print netns list

Observed on the Linux 3.18:

    # ip netns
    RTNETLINK answers: Operation not supported
    net0

CC: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Fixes: d182ee1307c7 ("ipnetns: allow to get and set netns ids")
Signed-off-by: Vadim Kochan <vadim4j@gmail.com>
3 files changed