io_uring/net: get rid of io_notif_complete_tw_ext

io_notif_complete_tw_ext() can be removed and combined with
io_notif_complete_tw to make it simpler without sacrificing
anything.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/025a124a5e20e2474a57e2f04f16c422eb83063c.1712534031.git.asml.silence@gmail.com


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