[PATCH] Make fio -W clean again

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/fio.h b/fio.h
index e279574..ca00a43 100644
--- a/fio.h
+++ b/fio.h
@@ -540,6 +540,6 @@
 #define fio_unused	__attribute((__unused__))
 
 #define for_each_file(td, f, i)	\
-	for ((i) = 0, (f) = &(td)->files[0]; (i) < (td)->nr_files; (i)++, (f) = &(td)->files[(i)])
+	for ((i) = 0, (f) = &(td)->files[0]; (i) < (int) (td)->nr_files; (i)++, (f) = &(td)->files[(i)])
 
 #endif