Leopard.

The change_user test failed because results of some statements
depended on platform and server build flags.

subselect_notembedded failure was a result of a bad merge from 5.0.

Fixed the corresponding test cases.


mysql-test/r/change_user.result:
  Fixed the test case.
mysql-test/r/subselect.result:
  Fixed the test case.
mysql-test/r/subselect_notembedded.result:
  Fixed the test case.
mysql-test/t/change_user.test:
  Fixed the test case.
mysql-test/t/subselect.test:
  Fixed the test case.
mysql-test/t/subselect_notembedded.test:
  Fixed the test case.