[PATCH RESEND] xfstests: fix compile error of src/fssum.c on bigendian host

[Rich Johnston]

This has been committed.

Thanks
--Rich

commit 3d2a446df422c5a1b9ab561ae73e66b68a5aa4c3
Author: Eryu Guan <eguan at redhat.com>
Date:   Tue Nov 12 04:16:53 2013 +0000

     xfstests: fix compile error of src/fssum.c on bigendian host