Add header with function definitions to quiet warnings and avoid future errors.

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>


--- a/net/dcb/dcbevent.c	2012-12-07 15:06:43.291665973 -0800
+++ b/net/dcb/dcbevent.c	2013-03-08 10:36:52.394147858 -0800
@@ -20,6 +20,7 @@
 #include <linux/rtnetlink.h>
 #include <linux/notifier.h>
 #include <linux/export.h>
+#include <net/dcbevent.h>
 
 static ATOMIC_NOTIFIER_HEAD(dcbevent_notif_chain);