can: peak_usb: correction of an initially misnamed field name

The data structure returned from the USB device contains a number
flashed by the user and not the serial number of the device.

Link: https://lore.kernel.org/all/20220719120632.26774-2-s.grosjean@peak-system.comSigned-off-by: Stephane Grosjean <s.grosjean@peak-system.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

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

@@ -439,7 +439,7 @@ static int pcan_usb_pro_get_device_id(struct peak_usb_device *dev,
 		return err;
 
 	pdn = (struct pcan_usb_pro_devid *)pc;
-	*device_id = le32_to_cpu(pdn->serial_num);
+	*device_id = le32_to_cpu(pdn->dev_num);
 
 	return err;
 }

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

@@ -112,7 +112,7 @@ struct __packed pcan_usb_pro_devid {
 	u8 data_type;
 	u8 channel;
 	__le16 dummy;
-	__le32 serial_num;
+	__le32 dev_num;
 };
 
 #define PCAN_USBPRO_LED_DEVICE		0x00