Need to clear ->files_size when ->files is cleared

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/init.c b/init.c
index 001e5c4..6fdd211 100644
--- a/init.c
+++ b/init.c
@@ -585,6 +585,7 @@
 		if (file_alloced) {
 			td_new->o.filename = NULL;
 			td_new->files_index = 0;
+			td_new->files_size = 0;
 			td_new->files = NULL;
 		}