Add a helper for task work execution code. We will use it later.
Reviewed-by: NPavel Begunkov <asml.silence@gmail.com>
Signed-off-by: NHao Xu <haoxu@linux.alibaba.com>
Link: https://lore.kernel.org/r/20211207093951.247840-4-haoxu@linux.alibaba.comSigned-off-by: NJens Axboe <axboe@kernel.dk>