[IP_TUNNEL]: Don't limit the number of tunnels with generic name explicitly.

Use the added dev_alloc_name() call to create tunnel device name,
rather than iterate in a hand-made loop with an artificial limit.

Thanks Patrick for noticing this.

[ The way this works is, when the device is actually registered,
  the generic code noticed the '%' in the name and invokes
  dev_alloc_name() to fully resolve the name.  -DaveM ]

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index 63f6917..906cb1a 100644
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -259,16 +259,8 @@
 
 	if (parms->name[0])
 		strlcpy(name, parms->name, IFNAMSIZ);
-	else {
-		int i;
-		for (i=1; i<100; i++) {
-			sprintf(name, "gre%d", i);
-			if (__dev_get_by_name(&init_net, name) == NULL)
-				break;
-		}
-		if (i==100)
-			goto failed;
-	}
+	else
+		sprintf(name, "gre%%d");
 
 	dev = alloc_netdev(sizeof(*t), name, ipgre_tunnel_setup);
 	if (!dev)