Fixed heap_btree test failure on 64-bit boxes.

mysql-test/t/heap_btree.test

@@ -169,8 +169,10 @@ DROP TABLE t1;
 #
 CREATE TABLE t1(val INT, KEY USING BTREE(val)) ENGINE=memory;
 INSERT INTO t1 VALUES(0);
+--replace_result 37 21
 SELECT INDEX_LENGTH FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_SCHEMA=DATABASE() AND TABLE_NAME='t1';
 UPDATE t1 SET val=1;
+--replace_result 37 21
 SELECT INDEX_LENGTH FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_SCHEMA=DATABASE() AND TABLE_NAME='t1';
 DROP TABLE t1;