can: gs_usb: gs_usb_get_timestamp(): fix endpoint parameter for usb_control_msg_recv()

can: gs_usb: gs_usb_get_timestamp(): fix endpoint parameter for usb_control_msg_recv()

The 2nd argument of usb_control_msg_recv() is the "endpoint",
usb_control_msg_recv() will internally convert the endpoint into a
pipe with usb_rcvctrlpipe().

In gs_usb_get_timestamp() not the endpoint "0" is passed, but the
pipe. This worked by accident as endpoint is a __u8 and the lowest 8
bits of the pipe are 0. Fix this copy/paste error by using the correct
endpoint of "0".

Fixes: c351fac8f5e8 ("can: gs_usb: add RX and TX hardware timestamp support")
Link: https://lore.kernel.org/all/20220920100416.959226-2-mkl@pengutronix.de
Cc: John Whittington <git@jbrengineering.co.uk>
Tested-by: John Whittington <git@jbrengineering.co.uk>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>