The return value of i2c_smbus_read_byte_data() is checked in
tmp401_init_client(), but only a warning is printed and the device is
registered anyway. This leads to devices being registered even if they
cannot be physically detected.

Bail out from probe in case of write errors and notify the user.
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>