Use view db name as thread default database, in order to ensure
that the view is parsed and prepared correctly.


mysql-test/r/sp.result:
  test result
mysql-test/t/sp.test:
  test case
sql/sql_parse.cc:
  copy thd->db_length to table_list->db_length
sql/sql_view.cc:
  Use view db name as thread default database, in order to ensure
  that the view is parsed and prepared correctly.