[NETNS]: Process devinet ioctl in the correct namespace.

Add namespace parameter to devinet_ioctl and locate device inside it for
state changes.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/ipconfig.c b/net/ipv4/ipconfig.c
index 10013cc..c90e75a 100644
--- a/net/ipv4/ipconfig.c
+++ b/net/ipv4/ipconfig.c
@@ -291,7 +291,7 @@
 
 	mm_segment_t oldfs = get_fs();
 	set_fs(get_ds());
-	res = devinet_ioctl(cmd, (struct ifreq __user *) arg);
+	res = devinet_ioctl(&init_net, cmd, (struct ifreq __user *) arg);
 	set_fs(oldfs);
 	return res;
 }