When verify fails, dump the good/bad blocks to files

This makes it easy to compare afterwards to see what kind of
corruption was experienced.

Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
diff --git a/fio.c b/fio.c
index 9c55670..e475a36 100644
--- a/fio.c
+++ b/fio.c
@@ -865,7 +865,7 @@
 				 * Fill the buffer with the pattern if we are
 				 * going to be doing writes.
 				 */
-				fill_pattern(td, io_u->buf, max_bs, io_u);
+				fill_pattern(td, io_u->buf, max_bs, io_u, 0, 0);
 			}
 		}