isci: save the i/o tag outside the scic request structure.

The pointer to the core representation of a request is marked NULL at
completion, but we need to save the i/o tag for task management.

Signed-off-by: Jeff Skirvin <jeffrey.d.skirvin@intel.com>
Signed-off-by: Jacek Danecki <Jacek.Danecki@intel.com>
[revise changelog]
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

drivers/scsi/isci/task.h

@@ -224,7 +224,7 @@ void isci_task_build_tmf(
 	void (*tmf_sent_cb)(
 		enum isci_tmf_cb_state,
 		struct isci_tmf *, void *),
-	void *cb_data);
+	struct isci_request *old_request);
 
 int isci_task_execute_tmf(
 	struct isci_host *isci_host,