rtc: s5m: convert to dev_err_probe() where appropriate

dev_err_probe() exists to simplify code and harmonise error messages,
there's no reason not to use it here.

Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: André Draszik <andre.draszik@linaro.org>
Link: https://lore.kernel.org/r/20250304-rtc-cleanups-v2-16-d4689a71668c@linaro.org


Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>