Try to stabilize main.innodb_ext_key,off

Thanks to Varun Gupta for suggesting this. This seems to
make main.innodb_ext_key,off more stable.

mysql-test/main/innodb_ext_key,off.rdiff

+--- innodb_ext_key.result
++++ innodb_ext_key,off.result
 @@ -9,7 +9,7 @@
  explain
  select count(*) from lineitem where l_orderkey=130 and l_shipdate='1992-07-01';

mysql-test/main/innodb_ext_key.result

@@ -26,12 +26,12 @@ Handler_read_rnd	0
 Handler_read_rnd_deleted	0
 Handler_read_rnd_next	0
 explain
-select count(*) from lineitem
+select count(*) from lineitem use index(primary)
 where l_orderkey=130 and l_linenumber=2 and l_shipdate='1992-07-01';
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	lineitem	const	PRIMARY,i_l_shipdate,i_l_orderkey,i_l_orderkey_quantity	PRIMARY	8	const,const	1	
+1	SIMPLE	lineitem	const	PRIMARY	PRIMARY	8	const,const	1	
 flush status;
-select count(*) from lineitem 
+select count(*) from lineitem use index(primary)
 where l_orderkey=130 and l_linenumber=2 and l_shipdate='1992-07-01';
 count(*)
 1

mysql-test/main/innodb_ext_key.test

@@ -17,6 +17,7 @@ use dbt3_s001;
 --disable_result_log
 --disable_warnings
 --source include/dbt3_s001.inc
+ANALYZE TABLE lineitem PERSISTENT FOR COLUMNS() INDEXES();
 --enable_warnings
 --enable_result_log
 --enable_query_log
@@ -28,10 +29,10 @@ select count(*) from lineitem where l_orderkey=130 and l_shipdate='1992-07-01';
 show status like 'handler_read%';
 
 explain
-select count(*) from lineitem
+select count(*) from lineitem use index(primary)
   where l_orderkey=130 and l_linenumber=2 and l_shipdate='1992-07-01';
 flush status;
-select count(*) from lineitem 
+select count(*) from lineitem use index(primary)
   where l_orderkey=130 and l_linenumber=2 and l_shipdate='1992-07-01';
 show status like 'handler_read%';