Better checks for disk util init

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/os/os.h b/os/os.h
index 104f4a8..e630627 100644
--- a/os/os.h
+++ b/os/os.h
@@ -57,7 +57,7 @@
 #endif
 
 #ifndef FIO_HAVE_RAWBIND
-#define fio_lookup_raw(dev, majdev, mindev)
+#define fio_lookup_raw(dev, majdev, mindev)	1
 #endif
 
 #endif