rtnetlink: ignore NETDEV_PRE_UP notifier in rtnetlink_event()

Commit 3b8bcfd5 (net: introduce pre-up netdev notifier) added a new
notifier which is run before a device is set UP for use by cfg80211.

The patch missed to add the new notifier to the ignore list in
rtnetlink_event(), so we currently get an unnecessary netlink
notification before a device is set UP.
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/core/rtnetlink.c

@@ -1432,6 +1432,7 @@ static int rtnetlink_event(struct notifier_block *this, unsigned long event, voi
 	case NETDEV_DOWN:
 		rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP|IFF_RUNNING);
 		break;
+	case NETDEV_PRE_UP:
 	case NETDEV_POST_INIT:
 	case NETDEV_REGISTER:
 	case NETDEV_CHANGE: