io_uring/net: fix notif cqe reordering

send zc is not restricted to !IO_URING_F_UNLOCKED anymore and so
we can't use task-tw ordering trick to order notification cqes
with requests completions. In this case leave it alone and let
io_send_zc_cleanup() flush it.

Cc: stable@vger.kernel.org
Fixes: 53bdc88a

 ("io_uring/notif: order notif vs send CQEs")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/0031f3a00d492e814a4a0935a2029a46d9c9ba06.1664486545.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>