Coding style police.  No functional change.

* subversion/libsvn_subr/time.c
  (human_timestamp_format_suffix): rename to ...
  (HUMAN_TIMESTAMP_FORMAT_SUFFIX): ... this since it's a #define
  (svn_time_to_human_cstring): update user

git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1533386 13f79535-47bb-0310-9956-ffa450edef68