ASoC: wm1250-ev1: Fix uninitialized ret

ASoC: wm1250-ev1: Fix uninitialized ret

The GPIO descriptor conversion patch left an unitialized ret behind
by mistake, fix it by getting rid of the variable altogether.

Fixes: 10a366f36e2a ("ASoC: wm1250-ev1: Convert to GPIO descriptors")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202312090953.DiUo3mue-lkp@intel.com/
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20231209-descriptors-sound-wlf-v1-1-5b885ce43ae1@linaro.org
Signed-off-by: Mark Brown <broonie@kernel.org>