iio: adc: rzg2l_adc: Remove unnecessary print function dev_err()

The print function dev_err() is redundant because
platform_get_irq() already prints an error.

Signed-off-by: Xu Wang <vulab@iscas.ac.cn>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Link: https://lore.kernel.org/r/20211105015504.39226-1-vulab@iscas.ac.cn


Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>