caif: remove wrong dev_net_set() call

commit 8997c27e upstream.

src_net points to the netns where the netlink message has been received. This
netns may be different from the netns where the interface is created (because
the user may add IFLA_NET_NS_[PID|FD]). In this case, src_net is the link netns.

It seems wrong to override the netns in the newlink() handler because if it
was not already src_net, it means that the user explicitly asks to create the
netdevice in another netns.

CC: Sjur Brændeland <sjur.brandeland@stericsson.com>
CC: Dmitry Tarnyagin <dmitry.tarnyagin@lockless.no>
Fixes: 8391c4aa ("caif: Bugfixes in CAIF netdevice for close and flow control")
Fixes: c4125400 ("caif-hsi: Add rtnl support")
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[lizf: Backported to 3.4: drop the change to drivers/net/caif/caif_hsi.c]
Signed-off-by: Zefan Li <lizefan@huawei.com>

net/caif/chnl_net.c

@@ -467,7 +467,6 @@ static int ipcaif_newlink(struct net *src_net, struct net_device *dev,
 	ASSERT_RTNL();
 	caifdev = netdev_priv(dev);
 	caif_netlink_parms(data, &caifdev->conn_req);
-	dev_net_set(caifdev->netdev, src_net);
 
 	ret = register_netdevice(dev);
 	if (ret)