Add verify trim support

Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
diff --git a/fio.c b/fio.c
index 1d20cf7..c8de2ee 100644
--- a/fio.c
+++ b/fio.c
@@ -1022,6 +1022,7 @@
 	INIT_FLIST_HEAD(&td->io_log_list);
 	INIT_FLIST_HEAD(&td->io_hist_list);
 	INIT_FLIST_HEAD(&td->verify_list);
+	INIT_FLIST_HEAD(&td->trim_list);
 	pthread_mutex_init(&td->io_u_lock, NULL);
 	td->io_hist_tree = RB_ROOT;