Do not expose vmm(4) VM IDs to the user, use vmd(8)'s IDs instead.

Do not expose vmm(4) VM IDs to the user, use vmd(8)'s IDs instead.

Each VM has two IDs: one from the kernel (vmm) and a different one
from userland (vmd).  The vmm ID is not consistent and incremented on
every boot during runtimg of the host system.  The vmd ID remains the
same during the lifetime of a configured VM, even after reboots.
Configured VMs will even get and keep their IDs when the configuration
is loaded.  This is more what users expect.

Pointed out and tested by otto@

OK deraadt@