pinctrl: ralink: Check for null return of devm_kcalloc

Because of the possible failure of the allocation, data->domains might
be NULL pointer and will cause the dereference of the NULL pointer
later.
Therefore, it might be better to check it and directly return -ENOMEM
without releasing data manually if fails, because the comment of the
devm_kmalloc() says "Memory allocated with this function is
automatically freed on driver detach.".

Fixes: a86854d0 ("treewide: devm_kzalloc() -> devm_kcalloc()")
Reported-by: Hacash Robot <hacashRobot@santino.com>
Signed-off-by: William Dean <williamsukatube@gmail.com>
Link: https://lore.kernel.org/r/20220710154922.2610876-1-williamsukatube@163.com


Signed-off-by: Linus Walleij <linus.walleij@linaro.org>