io_uring: propagate locking state to poll cancel

Poll cancellation will be soon need to grab ->uring_lock inside, pass
the locking state, i.e. issue_flags, inside the cancellation functions.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/b86781d047727c07163443b57551a3fa57c7c5e1.1655371007.git.asml.silence@gmail.com


Reviewed-by: Hao Xu <howeyxu@tencent.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>