Fix the typo in the constructor. Cover a semantic check that previously
never worked with a test.


mysql-test/r/create.result:
  Update results (Bug#26104)
mysql-test/r/innodb.result:
  Update results.
mysql-test/t/create.test:
  Add a test case for Bug#26104 Bug on foreign key class constructor
mysql-test/t/innodb.test:
  Return a new error number (MySQL error instead of internal InnoDB error).
sql/sql_class.h:
  A fix for Bug#26104 Bug on foreign key class constructor -- fix
  the typo in the constructor