Made the result output deterministic.

mysql-test/r/cte_recursive.result

@@ -1911,8 +1911,8 @@ a	b	distance	path_string
 2	6	4	2.1.3.5.6.
 2	7	2	2.4.7.
 2	7	4	2.1.3.4.7.
-3	1	2	3.6.1.
 3	1	2	3.5.1.
+3	1	2	3.6.1.
 3	1	3	3.5.6.1.
 3	4	1	3.4.
 3	5	1	3.5.

mysql-test/t/cte_recursive.test

@@ -1409,6 +1409,7 @@ DROP TABLE IF EXISTS edges2;
 CREATE VIEW edges2 (a, b) AS 
  SELECT a, b FROM edges   UNION ALL   SELECT b, a FROM edges;
 
+--sorted_result
 WITH RECURSIVE transitive_closure(a, b, distance, path_string) AS
 ( SELECT a, b, 1 AS distance,
    concat(a, '.', b, '.') AS path_string