Update test result: same as in 10.0 and maria (and mysql) 5.5

mysql-test/r/group_min_max_innodb.result

@@ -70,7 +70,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	index	NULL	PRIMARY	5	NULL	4	Using index; Using temporary
 explain select distinct f1, f2 from t1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	NULL	PRIMARY	5	NULL	3	Using index for group-by; Using temporary
+1	SIMPLE	t1	index	NULL	PRIMARY	5	NULL	4	Using index
 drop table t1;
 create table t1(pk int primary key) engine=innodb;
 create view v1 as select pk from t1 where pk < 20;