Issue time fixup for guasi/libaio

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/engines/guasi.c b/engines/guasi.c
index a7589dc..4ae0143 100644
--- a/engines/guasi.c
+++ b/engines/guasi.c
@@ -141,6 +141,9 @@
 	struct io_u *io_u;
 	struct timeval now;
 
+	if (!fio_fill_issue_time(td))
+		return;
+
 	io_u_mark_submit(td, nr);
 	fio_gettime(&now, NULL);
 	for (i = 0; i < nr; i++) {