bridge: defer switchdev fdb del call in fdb_del_external_learn

Since spinlock is held here, defer the switchdev operation. Also, ensure
that defered switchdev ops are processed before port master device
is unlinked.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/bridge/br_if.c b/net/bridge/br_if.c
index 45e4757..ec02f58 100644
--- a/net/bridge/br_if.c
+++ b/net/bridge/br_if.c
@@ -24,6 +24,7 @@
 #include <linux/slab.h>
 #include <net/sock.h>
 #include <linux/if_vlan.h>
+#include <net/switchdev.h>
 
 #include "br_private.h"
 
@@ -250,6 +251,8 @@
 
 	nbp_vlan_flush(p);
 	br_fdb_delete_by_port(br, p, 0, 1);
+	switchdev_deferred_process();
+
 	nbp_update_port_count(br);
 
 	netdev_upper_dev_unlink(dev, br->dev);