irqchip/renesas-rzg2l: Remove dev_err_probe() if error is -ENOMEM

The dev_err_probe() doesn't do anything when error is '-ENOMEM'.

Therefore, remove the useless call to dev_err_probe(), and just return the
value instead.

Signed-off-by: Xichao Zhao <zhao.xichao@vivo.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20250821093845.564496-1-zhao.xichao@vivo.com