Follow-up to r1755486: Improve docstring.
Follow-up to r1755486: Improve docstring.

Suggested by: danielsh

* subversion/include/svn_io.h
  (svn_stream_checksum): Improve docstring.


git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@1756647 13f79535-47bb-0310-9956-ffa450edef68

YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion