With new QEMU which supports migration events,
qemuMigrationCheckJobStatus needs to explicitly query QEMU for migration
statistics once migration is completed to make sure the caller sees
up-to-date statistics with both old and new QEMU. However, some callers
are not interested in the statistics at all and once we start waiting
for a completed migration on the destination host too, checking the
statistics would even fail. Let's push the decision whether to update
the statistics or not to the caller.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>