Review fixes

mysql-test/r/ctype_cp932.result:
  Remove first event to make things portable
mysql-test/r/rpl_drop_db.result:
  Use 'mysqltest' as database instead of 'd1'
  Made test faster by using longer table names instead of lots of tables
mysql-test/t/ctype_cp932.test:
  Remove first event to make things portable
mysql-test/t/rpl_drop_db.test:
  Use 'mysqltest' as database instead of 'd1'
  Made test faster by using longer table names instead of lots of tables
sql/sql_db.cc:
  Indentation & style fixes
  Simple optimization (remove constant and boolean variable)