block: Add blockdev-backup to transaction Signed-off-by: Fam Zheng <famz@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Markus Armbruster <armbru@redhat.com> Message-id: 1418899027-8445-4-git-send-email-famz@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>