io_uring: remove tctx->sqpoll

struct io_uring_task::sqpoll is not used anymore, kill it
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

fs/io_uring.c

@@ -464,7 +464,6 @@ struct io_uring_task {
 	struct io_wq		*io_wq;
 	struct percpu_counter	inflight;
 	atomic_t		in_idle;
-	bool			sqpoll;
 
 	spinlock_t		task_lock;
 	struct io_wq_work_list	task_list;