Fix hang when SD card fails to init

src/firmware.c

@@ -400,7 +400,9 @@ void firmware() {

    if (!sd_mount()) {
        error("Failed to init SD card!\n");
        return;
        print("Press any key to power off\n");
        btn_wait();
        i2c_send_byte(I2C_5, 0x3C, MAX77620_REG_ONOFFCNFG1, MAX77620_ONOFFCNFG1_PWR_OFF);
    }

    print("Welcome to ReiNX %s!\n", VERSION);