Clarify docstring.

* subversion/include/svn_io.h
  (svn_io_filesizes_three_different_p): 
    Clarify encoding requirement and error condition.


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1398346 13f79535-47bb-0310-9956-ffa450edef68
1 file changed