pinctrl: Don't override the error code in probe error handling

Otherwise, we return 0 in probe error paths when gpiochip_remove() returns 0.
Also show error message if gpiochip_remove() fails.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Acked-by: Tony Prisk <linux@prisktech.co.nz>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>