bridge_set_hello_time
if (bridge_set_hello_time(bif, val->v.integer) < 0)
bridge_set_hello_time(bif, ctx->scratch->int1);
if (bridge_set_hello_time(bif, val->v.integer) < 0)
bridge_set_hello_time(bif, ctx->scratch->int1);
int bridge_set_hello_time(struct bridge_if *bif, int32_t hello_time);