This adds get_data_transfer_info helper function that get lha and
sectors for READ_* and WRITE_* commands (and XDWRITEREAD_10 later).
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: Douglas Gilbert <dougg@torque.net>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>