scsi: libsas: Add spin_lock/unlock() to protect asd_sas_port->phy_list

Most places that use asd_sas_port->phy_list in libsas are protected by
spinlock asd_sas_port->phy_list_lock. However, there are still a few places
which miss the lock. Add it in those places.

Link: https://lore.kernel.org/r/1639999298-244569-5-git-send-email-chenxiang66@hisilicon.comReviewed-by: John Garry <john.garry@huawei.com>
Signed-off-by: Xiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/libsas/sas_event.c

@@ -104,11 +104,15 @@ void sas_enable_revalidation(struct sas_ha_struct *ha)
 		if (!test_and_clear_bit(ev, &d->pending))
 			continue;
 
-		if (list_empty(&port->phy_list))
+		spin_lock(&port->phy_list_lock);
+		if (list_empty(&port->phy_list)) {
+			spin_unlock(&port->phy_list_lock);
 			continue;
+		}
 
 		sas_phy = container_of(port->phy_list.next, struct asd_sas_phy,
 				port_phy_el);
+		spin_unlock(&port->phy_list_lock);
 		sas_notify_port_event(sas_phy,
 				PORTE_BROADCAST_RCVD, GFP_KERNEL);
 	}