sql/item_func.cc:
  Unused variable 'thd' removed.
sql/item_subselect.cc:
  Unused variable 'type' removed.
sql/slave.cc:
  Unused variable 'return_val' removed.
sql/sql_derived.cc:
  Unused variable 'is_subsel' removed.
sql/sql_parse.cc:
  Unused variables 'pstr' and 'create_info' removed.
sql/sql_prepare.cc:
  Unused variable 'res' removed.
sql/time.cc:
  Unused variable 'str_begin' removed.