Fix failing test case, re: bug 38195.

mysql-test/r/group_min_max.result

@@ -2392,8 +2392,8 @@ a	b
 0	11
 0	12
 explain extended select sql_buffer_result a, max(b)+1 from t1 where a = 0 group by a;
-id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	PRIMARY,index	PRIMARY	4	NULL	5	Using where; Using index for group-by; Using temporary
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	range	PRIMARY,index	PRIMARY	4	NULL	6	83.33	Using where; Using index for group-by; Using temporary
 Warnings:
 Note	1003	select sql_buffer_result `test`.`t1`.`a` AS `a`,(max(`test`.`t1`.`b`) + 1) AS `max(b)+1` from `test`.`t1` where (`test`.`t1`.`a` = 0) group by `test`.`t1`.`a`
 drop table t1;