qemu: Fix reporting completed migration stats on destination
    
    This has been broken since commit v4.0.0-165-g93412bb827 which added
    jobInfo->statsType enum to distinguish various statistics types. During
    migration the type will always be QEMU_DOMAIN_JOB_STATS_TYPE_MIGRATION,
    however the destination code consuming the statistics data from
    migration cookie failed to properly set the type. So even though
    everything was filled in, the type remained *_NONE and any attempt to
    fetch the statistics data of a completed migration on the destination
    host failed.
    
    https://bugzilla.redhat.com/show_bug.cgi?id=1584071
    
    Signed-off-by: Jiri Denemark <jdenemar@redhat.com>