smbios: Convert to error_report()

Improves diagnistics from ad hoc messages like

    Invalid SMBIOS UUID string

to

    qemu-system-x86_64: -smbios type=1,uuid=gaga: Invalid UUID

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Laszlo "ever the optimist" Ersek <lersek@redhat.com>
Message-id: 1370610036-10577-4-git-send-email-armbru@redhat.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
