io_uring/io-wq: kill off now unused IO_WQ_WORK_NO_CANCEL

It's no longer used as IORING_OP_CLOSE got rid for the need of flagging
it as uncancelable, kill it of.
Signed-off-by: Jens Axboe <axboe@kernel.dk>

fs/io-wq.c

@@ -944,7 +944,6 @@ static bool io_wq_worker_cancel(struct io_worker *worker, void *data)
 	 */
 	spin_lock_irqsave(&worker->lock, flags);
 	if (worker->cur_work &&
-	    !(worker->cur_work->flags & IO_WQ_WORK_NO_CANCEL) &&
 	    match->fn(worker->cur_work, match->data)) {
 		send_sig(SIGINT, worker->task, 1);
 		match->nr_running++;

fs/io-wq.h

@@ -9,7 +9,6 @@ enum {
 	IO_WQ_WORK_CANCEL	= 1,
 	IO_WQ_WORK_HASHED	= 2,
 	IO_WQ_WORK_UNBOUND	= 4,
-	IO_WQ_WORK_NO_CANCEL	= 8,
 	IO_WQ_WORK_CONCURRENT	= 16,
 
 	IO_WQ_WORK_FILES	= 32,

fs/io_uring.c

@@ -6386,11 +6386,8 @@ static struct io_wq_work *io_wq_submit_work(struct io_wq_work *work)
 	if (timeout)
 		io_queue_linked_timeout(timeout);
 
-	/* if NO_CANCEL is set, we must still run the work */
-	if ((work->flags & (IO_WQ_WORK_CANCEL|IO_WQ_WORK_NO_CANCEL)) ==
-				IO_WQ_WORK_CANCEL) {
+	if (work->flags & IO_WQ_WORK_CANCEL)
 		ret = -ECANCELED;
-	}
 
 	if (!ret) {
 		do {