io_uring: fix io_poll_remove_all clang warnings

clang complains on bitwise operations with bools, add a bit more
verbosity to better show that we want to call io_poll_remove_all_table()
twice but with different arguments.

Reported-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/f11d21dcdf9233e0eeb15fa13b858a05a78eb310.1655684496.git.asml.silence@gmail.com


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