move 'table_collation' field filling outside of if(file) condition
because this field has 'OPEN_FRM_ONLY' attribute


mysql-test/r/information_schema.result:
  test result
mysql-test/t/information_schema.test:
  test case
sql/sql_show.cc:
  move 'table_collation' field filling outside of if(file) condition
  because this field has 'OPEN_FRM_ONLY' attribute