Kernel warning via unconditional queue-affinity construction

Improper queue-affinity handling in Linux 6.4 allows local users to trigger a kernel warning through a virtio-vDPA network device. virtio_vdpa_find_vqs calls create_affinity_masks even when the driver supplies no affinity descriptor or the parent lacks set_vq_affinity support, and group_cpus_evenly assumes at least as many CPUs as queue groups. Reachability requires local access to configure or probe a virtio-vDPA device, particularly a network device whose queue count exceeds the CPU count; the documented result is a kernel warning rather than data access or code execution.