CAN: use dev_get_by_index_rcu

Use new function to avoid doing read_lock().
Signed-off-by: NStephen Hemminger <shemminger@vyatta.com>
Acked-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NOliver Hartkopp <oliver@hartkopp.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/can/bcm.c

@@ -139,13 +139,13 @@ static char *bcm_proc_getifname(char *result, int ifindex)
 	if (!ifindex)
 		return "any";
 
-	read_lock(&dev_base_lock);
-	dev = __dev_get_by_index(&init_net, ifindex);
+	rcu_read_lock();
+	dev = dev_get_by_index_rcu(&init_net, ifindex);
 	if (dev)
 		strcpy(result, dev->name);
 	else
 		strcpy(result, "???");
-	read_unlock(&dev_base_lock);
+	rcu_read_unlock();
 
 	return result;
 }