[SCSI] isci: No need to manage the pending reset bit on pending requests.

The lldd does not need to look at or manage the pending device
reset bit in pending sas_tasks.

Signed-off-by: Jeff Skirvin <jeffrey.d.skirvin@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>