Some test cases were missing preparation to deal with failed
predecessor test cases.

Added preparation (drop table if exists) to some test cases.


mysql-test/include/innodb_rollback_on_timeout.inc:
  Bug#32754 - InnoDB tests do not prepare or clean up correctly
  Added preparation (drop table if exists).
mysql-test/r/innodb-semi-consistent.result:
  Bug#32754 - InnoDB tests do not prepare or clean up correctly
  Fixed test result.
mysql-test/r/innodb-ucs2.result:
  Bug#32754 - InnoDB tests do not prepare or clean up correctly
  Fixed test result.
mysql-test/r/innodb_mysql.result:
  Bug#32754 - InnoDB tests do not prepare or clean up correctly
  Fixed test result.
mysql-test/r/innodb_timeout_rollback.result:
  Bug#32754 - InnoDB tests do not prepare or clean up correctly
  Fixed test result.
mysql-test/t/innodb-semi-consistent.test:
  Bug#32754 - InnoDB tests do not prepare or clean up correctly
  Added preparation (drop table if exists).
mysql-test/t/innodb-ucs2.test:
  Bug#32754 - InnoDB tests do not prepare or clean up correctly
  Added preparation (drop table if exists).