[SCSI] remove requeue feature from blk_insert_request()

blk_insert_request() has a unobivous feature of requeuing a
request setting REQ_SPECIAL|REQ_SOFTBARRIER.  SCSI midlayer
was the only user and as previous patches removed the usage,
remove the feature from blk_insert_request().  Only special
requests should be queued with blk_insert_request().  All
requeueing should go through blk_requeue_request().

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

drivers/scsi/scsi_lib.c

@@ -92,7 +92,7 @@ int scsi_insert_special_req(struct scsi_request *sreq, int at_head)
 	 */
 	sreq->sr_request->flags &= ~REQ_DONTPREP;
 	blk_insert_request(sreq->sr_device->request_queue, sreq->sr_request,
-		       	   at_head, sreq, 0);
+		       	   at_head, sreq);
 	return 0;
 }