[SCSI] microtek: use data accessors and !use_sg cleanup

  - use scsi_cmnd data accessors
  - Clean the !use_sg code paths

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
[jejb: merge conflict fix]
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>