[SCSI] isd200: use one-element sg list in issuing commands

[SCSI] isd200: use one-element sg list in issuing commands

  - This patch should be commited before:
    usb: transport - convert to accessors and !use_sg code path removal

  - isd200_action() was still using direct liniar pointers in issuing
    commands to the USB transport level. This is no longer supported,
    use one-element scatterlist instead.
  - Adjustment of command's length in the case of scsi-to-ata translation
    is now restored before return to queuecommand, since other wise it can
    leak BIOs.
  - isd200_action() return Error on unknown requests. Used to print an error
    but still try to send garbage cdb.
  - convert few places to scsi data accessors.
  - Todo: This file will need to be changed when scsi_cmnd changes to
    scsi_data_buffer or any other solution.

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Acked-by: Matthew Dharm <mdharm-scsi@one-eyed-alien.net>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>