can: gs_usb: gs_can_close(): don't complain about failed device reset during ndo_stop

When the USB device is unplugged, gs_can_close() (which implements the
struct net_device_ops::ndo_stop callback) is called. In this function
an attempt is made to shut down the USB device with a USB control
message. For disconnected devices this will fail and a warning message
is printed.

Silence the driver by removing the printout of the error message if
the reset command fails.

Link: https://lore.kernel.org/all/20230718-gs_usb-cleanups-v1-9-c3b9154ec605@pengutronix.deSigned-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

drivers/net/can/usb/gs_usb.c

@@ -1029,9 +1029,7 @@ static int gs_can_close(struct net_device *netdev)
 	dev->can.state = CAN_STATE_STOPPED;
 
 	/* reset the device */
-	rc = gs_cmd_reset(dev);
-	if (rc < 0)
-		netdev_warn(netdev, "Couldn't shutdown device (err=%d)", rc);
+	gs_cmd_reset(dev);
 
 	/* reset tx contexts */
 	for (rc = 0; rc < GS_MAX_TX_URBS; rc++) {