can: mcba_usb: mcba_usb_read_bulk_callback(): fix URB memory leak

In the Linux kernel, the following vulnerability has been resolved:

can: mcba_usb: mcba_usb_read_bulk_callback(): fix URB memory leak

Fix similar memory leak as in commit 7352e1d5932a ("can: gs_usb:

gs_usb_receive_bulk_callback(): fix URB memory leak").

In mcba_usb_probe() -> mcba_usb_start(), the URBs for USB-in transfers are

allocated, added to the priv->rx_submitted anchor and submitted. In the

complete callback mcba_usb_read_bulk_callback(), the URBs are processed and

resubmitted. In mcba_usb_close() -> mcba_urb_unlink() the URBs are freed by

calling usb_kill_anchored_urbs(&priv->rx_submitted).

However, this does not take into account that the USB framework unanchors

the URB before the complete function is called. This means that once an

in-URB has been completed, it is no longer anchored and is ultimately not

released in usb_kill_anchored_urbs().

Fix the memory leak by anchoring the URB in the

mcba_usb_read_bulk_callback()to the priv->rx_submitted anchor.