isci: unify remote_device event_handlers

Implement all states in scic_sds_remote_device_event() and delete
the state handler.
Reported-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

drivers/scsi/isci/remote_device.h

@@ -386,7 +386,6 @@ typedef void (*scic_sds_remote_device_ready_not_ready_handler_t)(
  *
  */
 struct scic_sds_remote_device_state_handler {
-	scic_sds_remote_device_event_handler_t event_handler;
 	scic_sds_remote_device_frame_handler_t frame_handler;
 };