gpio: rcar: NULL dereference on error in probe()

It's not obvious from the label name but "err1" tries to release
"p->irq_domain" which leads to a NULL dereference.

Fixes: 119f5e44 ('gpio: Renesas R-Car GPIO driver V3')

Cc: stable@vger.kernel.org
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>