[SCSI] gdth: fix to internal commands execution

[SCSI] gdth: fix to internal commands execution

The recent patch named:
  [SCSI] gdth: !use_sg cleanup and use of scsi accessors

has done a bad job in handling internal commands issued by gdth_execute().

Internal commands are issued with device gdth_cmd_str ready made directly
to the card, without any mapping or translations of scsi commands. So here
I added a gdth_cmd_str pointer to the gdth_cmndinfo private structure which
is then copied directly to host.

following this patch is a cleanup that removes the home cooked accessors
and reverts them to regular scsi_cmnd accessors. Since they are not used
anymore. After review maybe the 2 patches should be squashed together.

FIXME: There is still a problem with gdth_get_info(). as reported there
   is a WARN_ON trigerd in dma_free_coherent() when doing:
   $ cat /proc/sys/gdth/0

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Tested-by: Joerg Dorchain: <joerg@dorchain.net>
Tested-by: Stefan Priebe <s.priebe@allied-internet.ag>
Tested-by: Jon Chelton <jchelton@ffpglobal.com>
Cc: Stable Tree <stable@kernel.org>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>