[Commits] [wesnoth/wesnoth] ff3412: Avoid type mismatch warning.

[GitHub]

  Branch: refs/heads/master
  Home:   https://github.com/wesnoth/wesnoth
  Commit: ff3412b67ad42e45623e438b67f0271fdf9fc23e
      https://github.com/wesnoth/wesnoth/commit/ff3412b67ad42e45623e438b67f0271fdf9fc23e
  Author: Wedge009 <wedge009 at wedge009.net>
  Date:   2018-01-22 (Mon, 22 Jan 2018)

  Changed paths:
    M src/buffered_istream.hpp

  Log Message:
  -----------
  Avoid type mismatch warning.

std::streamsize definition says that negative values are never used (outside std::strstreambuf constructor).