orinoco: Annotate ezusb_xmit()

ezusb_xmit() sets ->in_rid in its request which means it does not wait
for an answer.

Use the ezusb_req_ctx_wait_skip() to denote that an answer is not
expected.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20201113212252.2243570-4-bigeasy@linutronix.de