i2c_mux_update
extern bool i2c_mux_update(i2c_txn_t *, i2c_ctrl_t *, i2c_port_t *,
if (!i2c_mux_update(txn, ctrl, port, &req->smbr_error)) {
if (!i2c_mux_update(txn, ctrl, port, &req->ir_error)) {