isci: unify remote_device start_io_handlers

Implement all states in scic_sds_remote_device_start_io() 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

@@ -386,12 +386,6 @@ typedef void (*scic_sds_remote_device_ready_not_ready_handler_t)(
  *
  */
 struct scic_sds_remote_device_state_handler {
-	/**
-	 * The start_io_handler specifies the method invoked when a user
-	 * attempts to start an IO request for a remote device.
-	 */
-	scic_sds_remote_device_request_handler_t start_io_handler;
-
 	/**
 	 * The complete_io_handler specifies the method invoked when a user
 	 * attempts to complete an IO request for a remote device.