Cleanup allocated resourses if there are errors,
otherwise it will trgger memleak.
Fixes: c9eb3e0f8701 ("net: dsa: Add support for learning FDB through notification") Signed-off-by: YueHaibing <yuehaibing@huawei.com> Reviewed-by: Vivien Didelot <vivien.didelot@gmail.com> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: David S. Miller <davem@davemloft.net>