Fix maria.maria test by updating test results.

"Distinct" optimization is not used by this query (both in this tree
and in mainline 10.2). Verified this in debugger.

mysql-test/suite/maria/maria.result

@@ -554,11 +554,11 @@ a
 explain select sql_big_result distinct t1.a from t1,t2 order by t2.a;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	system	NULL	NULL	NULL	NULL	1	Using temporary
-1	SIMPLE	t2	index	NULL	PRIMARY	4	NULL	2	Using index; Distinct
+1	SIMPLE	t2	index	NULL	PRIMARY	4	NULL	2	Using index
 explain select distinct t1.a from t1,t2 order by t2.a;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	system	NULL	NULL	NULL	NULL	1	Using temporary
-1	SIMPLE	t2	index	NULL	PRIMARY	4	NULL	2	Using index; Distinct
+1	SIMPLE	t2	index	NULL	PRIMARY	4	NULL	2	Using index
 drop table t1,t2;
 create table t1 (
 c1 varchar(32),