can: peak_usb: pcan_usb_{,pro}_get_device_id(): remove unneeded check for device_id

The callback struct peak_usb_adapter::dev_get_device_id, which is
implemented by the functions pcan_usb_{,pro}_get_device_id() is only
ever called with a valid device_id pointer.

This patch removes the unneeded check if the device_id pointer is
valid.

Link: https://lore.kernel.org/r/20210406111622.1874957-7-mkl@pengutronix.deAcked-by: Stephane Grosjean <s.grosjean@peak-system.com>
Tested-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.c

@@ -388,8 +388,8 @@ static int pcan_usb_get_device_id(struct peak_usb_device *dev, u32 *device_id)
 	err = pcan_usb_wait_rsp(dev, PCAN_USB_CMD_DEVID, PCAN_USB_GET, args);
 	if (err)
 		netdev_err(dev->netdev, "getting device id failure: %d\n", err);
-	else if (device_id)
-		*device_id = args[0];
+
+	*device_id = args[0];
 
 	return err;
 }

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

@@ -439,8 +439,7 @@ static int pcan_usb_pro_get_device_id(struct peak_usb_device *dev,
 		return err;
 
 	pdn = (struct pcan_usb_pro_devid *)pc;
-	if (device_id)
-		*device_id = le32_to_cpu(pdn->serial_num);
+	*device_id = le32_to_cpu(pdn->serial_num);
 
 	return err;
 }