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