scsi: smartpqi: Add controller cache flush during rmmod

Add in a call to flush the controller cache during driver removal.
Reviewed-by: Scott Benesh <scott.benesh@microchip.com>
Reviewed-by: Mike Mcgowan <mike.mcgowan@microchip.com>
Reviewed-by: Kevin Barnett <kevin.barnett@microchip.com>
Signed-off-by: Gilbert Wu <Gilbert.Wu@microchip.com>
Signed-off-by: Don Brace <don.brace@microchip.com>
Link: https://lore.kernel.org/r/166793532388.322537.878022136408270892.stgit@brunhildaSigned-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/smartpqi/smartpqi_init.c

@@ -9040,6 +9040,7 @@ static void pqi_pci_remove(struct pci_dev *pci_dev)
 {
 	struct pqi_ctrl_info *ctrl_info;
 	u16 vendor_id;
+	int rc;
 
 	ctrl_info = pci_get_drvdata(pci_dev);
 	if (!ctrl_info)
@@ -9051,6 +9052,13 @@ static void pqi_pci_remove(struct pci_dev *pci_dev)
 	else
 		ctrl_info->ctrl_removal_state = PQI_CTRL_GRACEFUL_REMOVAL;
 
+	if (ctrl_info->ctrl_removal_state == PQI_CTRL_GRACEFUL_REMOVAL) {
+		rc = pqi_flush_cache(ctrl_info, RESTART);
+		if (rc)
+			dev_err(&pci_dev->dev,
+				"unable to flush controller cache during remove\n");
+	}
+
 	pqi_remove_ctrl(ctrl_info);
 }