Same as ipv4 code, when ip6erspan_rcv call return PACKET_REJECT, we
should call icmpv6_send to send icmp unreachable message in error path.
Fixes: 5a963eb61b7c ("ip6_gre: Add ERSPAN native tunnel support") Acked-by: William Tu <u9012063@gmail.com> Cc: William Tu <u9012063@gmail.com> Signed-off-by: Haishuang Yan <yanhaishuang@cmss.chinamobile.com> Signed-off-by: David S. Miller <davem@davemloft.net>