[ATM]: Oops reading net/atm/arp

cat /proc/net/atm/arp causes the NULL pointer dereference in the
get_proc_net+0xc/0x3a. This happens as proc_get_net believes that the
parent proc dir entry contains struct net.

Fix this assumption for "net/atm" case.

The problem is introduced by the commit c0097b07abf5f92ab135d024dd41bd2aada1512f
from Eric W. Biederman/Daniel Lezcano.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/atm/proc.c b/net/atm/proc.c
index 5d9d5ffb..565e75e 100644
--- a/net/atm/proc.c
+++ b/net/atm/proc.c
@@ -476,7 +476,7 @@
 		if (e->dirent)
 			remove_proc_entry(e->name, atm_proc_root);
 	}
-	remove_proc_entry("atm", init_net.proc_net);
+	proc_net_remove(&init_net, "atm");
 }
 
 int __init atm_proc_init(void)
@@ -484,7 +484,7 @@
 	static struct atm_proc_entry *e;
 	int ret;
 
-	atm_proc_root = proc_mkdir("atm", init_net.proc_net);
+	atm_proc_root = proc_net_mkdir(&init_net, "atm", init_net.proc_net);
 	if (!atm_proc_root)
 		goto err_out;
 	for (e = atm_proc_ents; e->name; e++) {