CP-5841: Fixing the make and spec files for new RPM version.

Signed-off-by: Rob Dobson <rob@rdobson.co.uk>
Merge pull request #1 from rdobson/rpm_fixes

CP-5841: Fixing the make and spec files for new RPM version.
Merge pull request #2 from xenserver/xs-build_patch

Patch to make RPM build with Centos 6.4 RPM.