pinctrl: nomadik: fix dereference of error pointer

If nmk_gpio_populate_chip() returns an error, avoid deferencing its
return value.

Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/linux-gpio/5ee722f8-7582-420d-8477-45be6acde90f@moroto.mountain/


Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com>
Link: https://lore.kernel.org/r/20240306-mbly-gpio-err-fix-v1-1-a3605ba2336f@bootlin.com


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