mpt2sas: Call the _scsih_ir_shutdown prior to reporting the volumes missing from the OS

Issue:
IR shutdown(sending) and IR shutdown(complete) messages not listed in /var/log/messages when driver is removed.

The driver needs to issue a MPI2_RAID_ACTION_SYSTEM_SHUTDOWN_INITIATED request when the driver is unloaded so the IR metadata journal is updated. If this request is not sent, then the volume would need a "check consistency" issued on the next bootup if the volume was roamed from one initiator to another. The current driver supports this feature only when the system is rebooted, however this also need to be supported if the driver is unloaded

Fix:
To fix this issue, the driver is going
to need to call the _scsih_ir_shutdown prior to reporting the volumes missing from the OS, hence the device handles are still present.

---

index db287d7..5ded3db 100644
@@ -6665,6 +6665,7 @@ _scsih_remove(struct pci_dev *pdev)
 		destroy_workqueue(wq);
 
 	/* release all the volumes */
+	_scsih_ir_shutdown(ioc);
 	list_for_each_entry_safe(raid_device, next, &ioc->raid_device_list,
 	    list) {
 		if (raid_device->starget) {