innobase_mysql_tmpfile(): call dup() and my_close() on the file
  returned by create_temp_file()
  in order to avoid memory leak caused by my_open() being paired with close()


sql/ha_innodb.cc:
  innobase_mysql_tmpfile(): call dup() and my_close() on the file
  returned by create_temp_file()
  in order to avoid memory leak caused by my_open() being paired with close()