genirq/irq_sim: Shrink devm_irq_domain_create_sim()

The custom devres structure manages only a single pointer which can
can be achieved by using devm_add_action_or_reset() as well which
makes the code simpler.

[ tglx: Fixed return value handling - found by smatch ]

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20210301142659.8971-1-brgl@bgdev.pl