MDEV-14377 innodb_zip.cmp_per_index failed in buildbot, result length mismatch

- If select query chooses the index 'b' over clustered index then the issue
can happen. Changed the test case to use primary index for the select
query.

mysql-test/suite/innodb_zip/r/cmp_per_index.result

@@ -70,8 +70,17 @@ index_name	PRIMARY
 compress_ops	65
 compress_ops_ok	65
 uncompress_ops	0
+SHOW CREATE TABLE t;
+Table	t
+Create Table	CREATE TABLE `t` (
+  `a` int(11) NOT NULL,
+  `b` varchar(512) DEFAULT NULL,
+  `c` varchar(16) DEFAULT NULL,
+  PRIMARY KEY (`a`),
+  KEY `b` (`b`)
+) ENGINE=InnoDB DEFAULT CHARSET=latin1 KEY_BLOCK_SIZE=2
 SET GLOBAL innodb_cmp_per_index_enabled=ON;
-SELECT COUNT(*) FROM t;
+SELECT COUNT(*) FROM t IGNORE INDEX(b);
 COUNT(*)	128
 SELECT
 database_name,
@@ -85,15 +94,9 @@ FROM information_schema.innodb_cmp_per_index
 ORDER BY 1, 2, 3;
 database_name	test
 table_name	t
-index_name	b
-compress_ops	0
-compress_ops_ok	0
-uncompress_ops	6
-database_name	test
-table_name	t
 index_name	PRIMARY
 compress_ops	0
 compress_ops_ok	0
-uncompress_ops	5
+uncompress_ops	4
 DROP TABLE t;
 SET GLOBAL innodb_cmp_per_index_enabled=default;

mysql-test/suite/innodb_zip/t/cmp_per_index.test

@@ -98,9 +98,11 @@ ORDER BY 1, 2, 3;
 
 -- source include/restart_mysqld.inc
 
+SHOW CREATE TABLE t;
+
 SET GLOBAL innodb_cmp_per_index_enabled=ON;
 
-SELECT COUNT(*) FROM t;
+SELECT COUNT(*) FROM t IGNORE INDEX(b);
 
 SELECT
 database_name,