bridge: add tracepoint in br_fdb_update

This extends bridge fdb table tracepoints to also cover
learned fdb entries in the br_fdb_update path. Note that
unlike other tracepoints I have moved this to when the fdb
is modified because this is in the datapath and can generate
a lot of noise in the trace output. br_fdb_update is also called
from added_by_user context in the NTF_USE case which is already
traced ..hence the !added_by_user check.

Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Acked-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/bridge/br_fdb.c b/net/bridge/br_fdb.c
index be5e1da..4ea5c8b 100644
--- a/net/bridge/br_fdb.c
+++ b/net/bridge/br_fdb.c
@@ -583,8 +583,10 @@ void br_fdb_update(struct net_bridge *br, struct net_bridge_port *source,
 				fdb->updated = now;
 			if (unlikely(added_by_user))
 				fdb->added_by_user = 1;
-			if (unlikely(fdb_modified))
+			if (unlikely(fdb_modified)) {
+				trace_br_fdb_update(br, source, addr, vid, added_by_user);
 				fdb_notify(br, fdb, RTM_NEWNEIGH);
+			}
 		}
 	} else {
 		spin_lock(&br->hash_lock);
@@ -593,6 +595,7 @@ void br_fdb_update(struct net_bridge *br, struct net_bridge_port *source,
 			if (fdb) {
 				if (unlikely(added_by_user))
 					fdb->added_by_user = 1;
+				trace_br_fdb_update(br, source, addr, vid, added_by_user);
 				fdb_notify(br, fdb, RTM_NEWNEIGH);
 			}
 		}