Finish is the final state in v2 of our migration protocol. If something
fails, we have no option to abort the migration and resume the original
domain. Non fatal errors (such as failure to start guest CPUs or make
the domain persistent) has to be treated as success. Keeping the domain
running while reporting the failure was just asking for trouble.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>