- fix a typo bug in has_eqref_access_candidate()
- Adjust test to remove race condition

mysql-test/r/mysql-bug41486.result:
  Adjust test to remove race condition
mysql-test/t/mysql-bug41486.test:
  Adjust test to remove race condition
sql/item.cc:
  MWL#17: Table elimination:
    fix a typo bug in has_eqref_access_candidate()