Fix bad interaction with file open/close and queuing

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/ioengines.c b/ioengines.c
index d3ee4b9..9e1c556 100644
--- a/ioengines.c
+++ b/ioengines.c
@@ -327,8 +327,7 @@
 		}
 	}
 
-	f->last_free_lookup = 0;
-	f->last_pos = f->file_offset;
+	fio_file_reset(f);
 	f->flags |= FIO_FILE_OPEN;
 	f->flags &= ~FIO_FILE_CLOSING;