io_uring/napi: pass ktime to io_napi_adjust_timeout

Pass the waiting time for __io_napi_adjust_timeout as ktime and get rid
of all timespec64 conversions. It's especially simpler since the caller
already have a ktime.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/4f5b8e8eed4f53a1879e031a6712b25381adc23d.1722003776.git.asml.silence@gmail.com


Signed-off-by: Jens Axboe <axboe@kernel.dk>