Postfix for bug#22331 for windows platform.
explain.test, explain.result:
  Cleanup after bugfix#22331.


mysql-test/t/explain.test:
  Cleanup after bugfix#22331.
mysql-test/r/explain.result:
  Cleanup after bugfix#22331.
sql/sql_select.cc:
  Postfix for bug#22331 for windows platform.