spec: properly expand macros defined in .spec file
spec: properly expand macros defined in .spec file

Make sure to load rpm.spec before macro expansion so that macros defined in
.spec file are properly expaned.

Also expand macros in spec.get_nvr() to get proper NVR even for packages
with macros in Name.

Change-Id: I3679e7e855d2550554ba26532bb9f4ab15ddbc3f

openstack-packages/rdopkg,redhat-openstack/rdopkg,redhat-openstack/rdopkg,openstack-packages/rdopkg