[SCSI] aha152x: Use scsi_eh API for REQUEST_SENSE invocation

  - Use new scsi_eh_prep/restor_cmnd() for synchronous
    REQUEST_SENSE invocation.

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>