netns: return RTM_NEWNSID instead of RTM_GETNSID on a get

Usually, RTM_NEWxxx is returned on a get (same as a dump).

Fixes: 0c7aecd4bde4 ("netns: add rtnl cmd to add and get peer netns ids")
Signed-off-by: Nicolas Dichtel <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

net/core/net_namespace.c

···
 	}
 
 	err = rtnl_net_fill(msg, NETLINK_CB(skb).portid, nlh->nlmsg_seq, 0,
-			    RTM_GETNSID, net, peer, -1);
+			    RTM_NEWNSID, net, peer, -1);
 	if (err < 0)
 		goto err_out;