Assign unique name to each fake nova-compute

Without a unique name, the scheduler (and anything else, really) will
consider each of these nova-compute processes as being one and the same,
so only one entry in the services table, only one hypervisor seen by the
scheduler, etc. Assigning unique names lets us simulate an arbitrary
amount of nova-computes which is very handy for benchmarking the
scheduler.

Change-Id: Ie03aad81bd2a8e73b876a9eae934bc00bf2f71e9
Merge "Assign unique name to each fake nova-compute"