netns: return RTM_NEWNSID instead of RTM_GETNSID on a get

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

Fixes: 0c7aecd4 ("netns: add rtnl cmd to add and get peer netns ids")
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/core/net_namespace.c

@@ -601,7 +601,7 @@ static int rtnl_net_getid(struct sk_buff *skb, struct nlmsghdr *nlh)
 	}
 
 	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;