The product of sockets * dies * cores * threads must be equal to the
vCPU count. While libvirt and QEMU will report this error scenario,
it makes sense to catch it in virt-install, so we can test our local
logic for setting defaults for topology.
This exposes some inconsistent configurations in the test suite.
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>