!io_file_supports_async() case of io_read() is hard to read, it jumps
somewhere in the middle of the function just to do async setup and fail
on a similar check. Call io_setup_async_rw() directly for this case,
it's much easier to follow.
Signed-off-by: NPavel Begunkov <asml.silence@gmail.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>