A few minor improvements and simplifications to the svn_checksum code. Followup to r32524.
A few minor improvements and simplifications to the svn_checksum code.
Followup to r32524.

Suggested by: gstein

* subversion/libsvn_subr/checksum.c
  (DIGESTSIZE, validate_kind): New.
  (svn_checksum_create, svn_checksum_clear, svn_checksum_parse_hex,
   svn_checksum_dup, svn_checksum): Refactor the size and validation
   calculations using the new function and macro.


git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@872604 13f79535-47bb-0310-9956-ffa450edef68

wbond/subversion,YueLinHo/Subversion,wbond/subversion,wbond/subversion,YueLinHo/Subversion,wbond/subversion,YueLinHo/Subversion,wbond/subversion,wbond/subversion,wbond/subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion