Follow-up to r1573371: missed one conversion.

* subversion/libsvn_subr/fnv1a.c
  (svn_fnv1a_32__finalize): The checksum value must not depend on
                            platform endianess.

git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1573375 13f79535-47bb-0310-9956-ffa450edef68