An attempt to open file with name '????????.frm'
can produce different errors:
- ER_NO_SUCH_TABLE on Unix
- ER_FILE_NOT_FOUND on Windows
because QUESTION MARK has special meaning on Windows.
Make sure that any of these two errors happens.


mysql-test/r/show_check.result:
  Additional fix for bug N26402
mysql-test/t/show_check.test:
  Additional fix for bug N26402