[PATCH] aio example should use O_DIRECT IO

Otherwise it isn't async. Since fio defaults to buffered IO now, we need
to correct this example.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/examples/aio-read b/examples/aio-read
index 7300c33..173a4e1 100644
--- a/examples/aio-read
+++ b/examples/aio-read
@@ -1,6 +1,7 @@
 ; Read 4 files with aio at different depths
 [global]
 ioengine=libaio
+buffered=0
 rw=randread
 bs=128k
 size=512m