can: c_can: remove unused code

Commit 9d23a981 ("can: c_can: Remove unused inline function") left
behind C_CAN_MSG_OBJ_TX_LAST constant.

Commit fa39b54c ("can: c_can: Get rid of pointless interrupts") left
behind C_CAN_MSG_RX_LOW_LAST and C_CAN_MSG_OBJ_RX_SPLIT constants.

The removed code also made a comment useless and misleading.

Link: https://lore.kernel.org/r/20210302215435.18286-2-dariobin@libero.itSigned-off-by: Dario Binacchi <dariobin@libero.it>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

drivers/net/can/c_can/c_can.c

@@ -822,8 +822,7 @@ static inline u32 c_can_get_pending(struct c_can_priv *priv)
  * c_can core saves a received CAN message into the first free message
  * object it finds free (starting with the lowest). Bits NEWDAT and
  * INTPND are set for this message object indicating that a new message
- * has arrived. To work-around this issue, we keep two groups of message
- * objects whose partitioning is defined by C_CAN_MSG_OBJ_RX_SPLIT.
+ * has arrived.
  *
  * We clear the newdat bit right away.
  *

drivers/net/can/c_can/c_can.h

@@ -32,11 +32,7 @@
 				C_CAN_MSG_OBJ_RX_NUM - 1)
 
 #define C_CAN_MSG_OBJ_TX_FIRST	(C_CAN_MSG_OBJ_RX_LAST + 1)
-#define C_CAN_MSG_OBJ_TX_LAST	(C_CAN_MSG_OBJ_TX_FIRST + \
-				C_CAN_MSG_OBJ_TX_NUM - 1)
 
-#define C_CAN_MSG_OBJ_RX_SPLIT	9
-#define C_CAN_MSG_RX_LOW_LAST	(C_CAN_MSG_OBJ_RX_SPLIT - 1)
 #define RECEIVE_OBJECT_BITS	0x0000ffff
 
 enum reg {