Merge a change from MySQL:

  ------------------------------------------------------------
  revno: 2747
  committer: Timothy Smith <timothy.smith@sun.com>
  branch nick: 51
  timestamp: Fri 2009-01-16 17:49:07 +0100
  message:
    Add another cast to ignore int/ulong difference in error types, silence warning on Win64
  modified:
    storage/innobase/handler/ha_innodb.cc