libsas: remove task_collector mode

The task_collector mode (or "latency_injector", (C) Dan Willians) is an
optional I/O path in libsas that queues up scsi commands instead of
directly sending it to the hardware.  It generall increases latencies
to in the optiomal case slightly reduce mmio traffic to the hardware.

Only the obsolete aic94xx driver and the mvsas driver allowed to use
it without recompiling the kernel, and most drivers didn't support it
at all.

Remove the giant blob of code to allow better optimizations for scsi-mq
in the future.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Dan Williams <dan.j.williams@intel.com>
diff --git a/drivers/scsi/pm8001/pm8001_sas.h b/drivers/scsi/pm8001/pm8001_sas.h
index f6b2ac5..8dd8b78 100644
--- a/drivers/scsi/pm8001/pm8001_sas.h
+++ b/drivers/scsi/pm8001/pm8001_sas.h
@@ -623,8 +623,7 @@
 	void *funcdata);
 void pm8001_scan_start(struct Scsi_Host *shost);
 int pm8001_scan_finished(struct Scsi_Host *shost, unsigned long time);
-int pm8001_queue_command(struct sas_task *task, const int num,
-	gfp_t gfp_flags);
+int pm8001_queue_command(struct sas_task *task, gfp_t gfp_flags);
 int pm8001_abort_task(struct sas_task *task);
 int pm8001_abort_task_set(struct domain_device *dev, u8 *lun);
 int pm8001_clear_aca(struct domain_device *dev, u8 *lun);