While devm_gpiod_get_index_optional() returns NULL if the GPIO is not
present (i.e. -ENOENT), it may still return other error codes, like
-EPROBE_DEFER. Currently these are not handled, leading to
unrecoverable failures later in case of probe deferral:
Fixes: f3186dd876697e69 ("spi: Optionally use GPIO descriptors for CS GPIOs") Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Mark Brown <broonie@kernel.org>