Fix style
storage: fix a bug that no record returns with multiple column index

Redmine: #2651

Reported by foamcentime. Thanks!!
Reported by Naoya Murakami. Thanks!!

It is occurred when

  * columns indexed by multiple column index are used in order in WHERE and
  * a column indexed by multiple column index but it's not the first
    column is used in ORDER BY

See test cases in this commit for details.