tests: convert multifd migration tests to use common helper
Most of the multifd migration test logic is common with the rest of the
precopy tests, so it can use the helper without difficulty. The only
exception of the multifd cancellation test which tries to run multiple
migrations in a row.
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <
20220426160048.812266-7-berrange@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>