isci: fix scic_sds_remote_device_terminate_requests

Commit 0815632 "isci: unify remote_device stop_handlers" introduced the
possibility that not all requests get terminated if we reach the
request_count.  Now that we properly reference count devices we don't
need this self-defense and can do the straightforward scan of all active
requests.

Reported-by: Jeff Skirvin <jeffrey.d.skirvin@intel.com>
Acked-by: Jeff Skirvin <jeffrey.d.skirvin@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>