I2CRegisterMap panics when reading with offset 0

[Disasm]

#[test]
fn check_read_0() {
    let mut i2c = MockI2CDevice::new();
    let value = i2c.smbus_read_byte_data(0).unwrap();
    assert_eq!(value, 0);
}

This code panics with attempt to subtract with overflow because offset is no longer incremented inside I2CRegisterMap::read after 6671e87. Probably it should be incremented.