can: kvaser_usb: Refactor kvaser_usb_get_endpoints()

Replace parameters with struct kvaser_usb pointer. Rename the function
from kvaser_usb_get_endpoints() to kvaser_usb_setup_endpoints().

Signed-off-by: Jimmy Assarsson <extja@kvaser.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>