io_uring: correct io_queue_async_work() traces

Request's io-wq work is hashed in io_prep_async_link(), so
as trace_io_uring_queue_async_work() looks at it should follow after
prep has been done.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/709c9f872f4d2e198c7aed9c49019ca7095dd24d.1616366969.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

fs/io_uring.c

@@ -1239,10 +1239,10 @@ static void io_queue_async_work(struct io_kiocb *req)
 	BUG_ON(!tctx);
 	BUG_ON(!tctx->io_wq);
 
-	trace_io_uring_queue_async_work(ctx, io_wq_is_hashed(&req->work), req,
-					&req->work, req->flags);
 	/* init ->work of the whole link before punting */
 	io_prep_async_link(req);
+	trace_io_uring_queue_async_work(ctx, io_wq_is_hashed(&req->work), req,
+					&req->work, req->flags);
 	io_wq_enqueue(tctx->io_wq, &req->work);
 	if (link)
 		io_queue_linked_timeout(link);