can: peak_usb: pcan_usb_pro_encode_msg(): use macros for flags instead of plain integers

This patch replaces the plain integers used for flags in
pcan_usb_pro_encode_msg() by macros which are already defined.

Link: https://lore.kernel.org/r/20210309082128.23125-4-s.grosjean@peak-system.comSigned-off-by: Stephane Grosjean <s.grosjean@peak-system.com>
[mkl: split into two patches]
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

drivers/net/can/usb/peak_usb/pcan_usb_pro.c

@@ -776,9 +776,9 @@ static int pcan_usb_pro_encode_msg(struct peak_usb_device *dev,
 
 	flags = 0;
 	if (cf->can_id & CAN_EFF_FLAG)
-		flags |= 0x02;
+		flags |= PCAN_USBPRO_EXT;
 	if (cf->can_id & CAN_RTR_FLAG)
-		flags |= 0x01;
+		flags |= PCAN_USBPRO_RTR;
 
 	pcan_msg_add_rec(&usb_msg, data_type, 0, flags, len, cf->can_id,
 			 cf->data);