switchdev: Remove redundant variable

Instead of storing return value in 'err' and returning, just return
directly.

Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/switchdev/switchdev.c

@@ -624,13 +624,10 @@ EXPORT_SYMBOL_GPL(unregister_switchdev_notifier);
 int call_switchdev_notifiers(unsigned long val, struct net_device *dev,
 			     struct switchdev_notifier_info *info)
 {
-	int err;
-
 	ASSERT_RTNL();
 
 	info->dev = dev;
-	err = raw_notifier_call_chain(&switchdev_notif_chain, val, info);
-	return err;
+	return raw_notifier_call_chain(&switchdev_notif_chain, val, info);
 }
 EXPORT_SYMBOL_GPL(call_switchdev_notifiers);