rtnetlink: bring NETDEV_CHANGEUPPER event process back in rtnetlink_event

libteam needs this event notification in userspace when dev's master
dev has been changed. After this, the redundant notifications issue
would be fixed in the later patch 'rtnetlink: check DO_SETLINK_NOTIFY
correctly in do_setlink'.

Fixes: b6b36eb2 ("rtnetlink: Do not generate notifications for NETDEV_CHANGEUPPER event")
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Acked-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/core/rtnetlink.c

@@ -4286,6 +4286,7 @@ static int rtnetlink_event(struct notifier_block *this, unsigned long event, voi
 	case NETDEV_BONDING_FAILOVER:
 	case NETDEV_POST_TYPE_CHANGE:
 	case NETDEV_NOTIFY_PEERS:
+	case NETDEV_CHANGEUPPER:
 	case NETDEV_RESEND_IGMP:
 	case NETDEV_CHANGEINFODATA:
 	case NETDEV_CHANGE_TX_QUEUE_LEN: