Reversed the changes to fix bug #12095 after review
  done by SergeyG. Applied a fix suggested by him.


sql/sql_class.h:
  Reversed the changes to fix bug #12095 after review
  done by SergeyG. Applied a fix suggested by him.
sql/sql_select.cc:
  Reversed the changes to fix bug #12095 after review
  done by SergeyG. Applied a fix suggested by him.