can: af_can: remove NULL-ptr checks from users of can_dev_rcv_lists_find()

Since using the "struct can_ml_priv" for the per device "struct
dev_rcv_lists" the call can_dev_rcv_lists_find() cannot fail anymore.
This patch simplifies af_can by removing the NULL pointer checks from
the dev_rcv_lists returned by can_dev_rcv_lists_find().
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

net/can/af_can.c

@@ -462,7 +462,6 @@ int can_rx_register(struct net *net, struct net_device *dev, canid_t can_id,
 	spin_lock(&net->can.rcvlists_lock);
 
 	dev_rcv_lists = can_dev_rcv_lists_find(net, dev);
-	if (dev_rcv_lists) {
 	rcv_list = can_rcv_list_find(&can_id, &mask, dev_rcv_lists);
 
 	rcv->can_id = can_id;
@@ -479,11 +478,6 @@ int can_rx_register(struct net *net, struct net_device *dev, canid_t can_id,
 	rcv_lists_stats->rcv_entries++;
 	rcv_lists_stats->rcv_entries_max = max(rcv_lists_stats->rcv_entries_max,
 					       rcv_lists_stats->rcv_entries);
-	} else {
-		kmem_cache_free(rcv_cache, rcv);
-		err = -ENODEV;
-	}
-
 	spin_unlock(&net->can.rcvlists_lock);
 
 	return err;
@@ -530,12 +524,6 @@ void can_rx_unregister(struct net *net, struct net_device *dev, canid_t can_id,
 	spin_lock(&net->can.rcvlists_lock);
 
 	dev_rcv_lists = can_dev_rcv_lists_find(net, dev);
-	if (!dev_rcv_lists) {
-		pr_err("BUG: receive list not found for dev %s, id %03X, mask %03X\n",
-		       DNAME(dev), can_id, mask);
-		goto out;
-	}
-
 	rcv_list = can_rcv_list_find(&can_id, &mask, dev_rcv_lists);
 
 	/* Search the receiver list for the item to delete.  This should
@@ -668,7 +656,6 @@ static void can_receive(struct sk_buff *skb, struct net_device *dev)
 
 	/* find receive list for this device */
 	dev_rcv_lists = can_dev_rcv_lists_find(net, dev);
-	if (dev_rcv_lists)
 	matches += can_rcv_filter(dev_rcv_lists, skb);
 
 	rcu_read_unlock();