io_uring: kill an outdated comment

Request referencing has changed a while ago and there is no notion left
of submission/completion references, kill an outdated comment.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/38902e7229d68cecd62702436d627d4858b0d9d4.1662639236.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

io_uring/io_uring.c

@@ -1885,10 +1885,6 @@ static void io_queue_async(struct io_kiocb *req, int ret)
 		io_req_task_queue(req);
 		break;
 	case IO_APOLL_ABORTED:
-		/*
-		 * Queued up for async execution, worker will release
-		 * submit reference when the iocb is actually submitted.
-		 */
 		io_kbuf_recycle(req, 0);
 		io_queue_iowq(req, NULL);
 		break;