can: Speed up CAN frame receiption by using ml_priv

this patch removes the hlist that contains the CAN receiver filter lists.
It uses the 'midlayer private' pointer ml_priv and links the filters directly
to the CAN netdevice, which allows to omit the walk through the complete CAN
devices hlist for each received CAN frame.

This patch is tested and does not remove any locking.

Signed-off-by: Oliver Hartkopp <oliver@hartkopp.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/can/af_can.h b/net/can/af_can.h
index 18f91e3..34253b8 100644
--- a/net/can/af_can.h
+++ b/net/can/af_can.h
@@ -63,10 +63,8 @@
 
 enum { RX_ERR, RX_ALL, RX_FIL, RX_INV, RX_EFF, RX_MAX };
 
+/* per device receive filters linked at dev->ml_priv */
 struct dev_rcv_lists {
-	struct hlist_node list;
-	struct rcu_head rcu;
-	struct net_device *dev;
 	struct hlist_head rx[RX_MAX];
 	struct hlist_head rx_sff[0x800];
 	int remove_on_zero_entries;