Only start messagebus on RedHat.

This work around is only required on RedHat so use operatingsystem
instead of osfamily.

Change-Id: I85f780753aa9b4d579a62777fe96177daecaf622

manifests/compute/libvirt.pp

@@ -15,7 +15,7 @@ class nova::compute::libvirt (
     }
   }
 
-  if($::osfamily == 'RedHat') {
+  if($::operatingsystem == 'RedHat') {
     service { 'messagebus':
       ensure   => running,
       enable   => true,

spec/classes/nova_compute_libvirt_spec.rb

@@ -161,12 +161,6 @@ describe 'nova::compute::libvirt' do
         :require  => 'Package[libvirt]',
         :before   => 'Service[nova-compute]'
       )}
-      it { should contain_service('messagebus').with(
-        :ensure   => 'running',
-        :enable   => true,
-        :before   => 'Service[libvirt]',
-        :provider => nil
-      ) }
 
       it { should contain_nova_config('compute_driver').with_value('libvirt.LibvirtDriver')}
       it { should contain_nova_config('libvirt_type').with_value('kvm')}