libvirt: Stub out 'nova.virt.libvirt.utils.get_arch'
libvirt: Stub out 'nova.virt.libvirt.utils.get_arch'

Ensure consistent behavior across all hosts, regardless of architecture.
X86_64 is chosen as the default for obvious reasons.

A useless stub of 'nova.compute.utils.get_machine_ips' is removed. This
is already handled by the 'FakeLibvirtFixture'.

Change-Id: Icf55488e61793d5b055d230c8524df8210cd00fd
Signed-off-by: Stephen Finucane <4725dc7f3632bf126d9fbdc30c347e91e8d2fe16@redhat.com>

mahak/nova,mahak/nova,openstack/nova,openstack/nova,mahak/nova,openstack/nova