can: mcba_usb: cancel urb on -EPROTO

When we unplug the device, we can see both -EPIPE and -EPROTO depending
on exact timing and what system we run on. If we continue to resubmit
URBs, they will immediately fail, and they can cause stalls, especially
on slower CPUs.

Fix this by not resubmitting on -EPROTO, as we already do on -EPIPE.

Signed-off-by: Martin Kelly <mkelly@xevo.com>
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>