rtnetlink: ignore NETDEV_PRE_UP notifier in rtnetlink_event()

Commit 3b8bcfd (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: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 4dd4c3c..b7c7dfd 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -1432,6 +1432,7 @@
 	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: