[SCSI] isci: fix event-get pointer increment

Hardware only increments the put pointer on event types >= 4.  Do not
increment the get pointer for event type 3.
Reported-by: Kapil Karkra <kapil.karkra@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

drivers/scsi/isci/host.c

@@ -531,6 +531,9 @@ static void sci_controller_process_completions(struct isci_host *ihost)
 			break;
 
 		case SCU_COMPLETION_TYPE_EVENT:
+			sci_controller_event_completion(ihost, ent);
+			break;
+
 		case SCU_COMPLETION_TYPE_NOTIFY: {
 			event_cycle ^= ((event_get+1) & SCU_MAX_EVENTS) <<
 				       (SMU_COMPLETION_QUEUE_GET_EVENT_CYCLE_BIT_SHIFT - SCU_MAX_EVENTS_SHIFT);