io_uring: drop file refs after task cancel

stable inclusion
from stable-5.10.9
commit 94dbb87fc0b25285a0eba2350f77316063151be5
bugzilla: 47457

--------------------------------

[ Upstream commit de7f1d9e ]

io_uring fds marked O_CLOEXEC and we explicitly cancel all requests
before going through exec, so we don't want to leave task's file
references to not our anymore io_uring instances.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Chen Jun <chenjun102@huawei.com>
Acked-by: Xie XiuQi <xiexiuqi@huawei.com>