lwtunnel_get_encap_size
int lwtunnel_get_encap_size(struct lwtunnel_state *lwtstate);
EXPORT_SYMBOL_GPL(lwtunnel_get_encap_size);
nh_encapsize += lwtunnel_get_encap_size(
sz += lwtunnel_get_encap_size(nhi->fib_nhc.nhc_lwtstate);
*nexthop_len += lwtunnel_get_encap_size(nh->fib_nh_lws);
nexthop_len += lwtunnel_get_encap_size(nh->fib_nh_lws);