Fix signed/unsigned mismatch warning.
Fix signed/unsigned mismatch warning.

* subversion/libsvn_subr/checksum.c
  (svn__digest_to_cstring_display): Use apr_size_t instead int for index.


git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@1577070 13f79535-47bb-0310-9956-ffa450edef68

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