staging/lustre: fix build on non-x86

On non-x86 we will build with Lustre's errno translate code but
it has a few issues.

Cc: Andreas Dilger <andreas.dilger@intel.com>
Signed-off-by: Peng Tao <tao.peng@emc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>