scsi: sas: remove sas_domain_release_transport

sas_domain_release_transport is unused since at least v3.13, remove it.

Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>