ASoC: alc56(23|32): fix undefined return value of probing code

Commit 5d6be5aa

 ("ASoC: codec: Simplify ASoC probe code.") left variable
'ret', whose value is returned, uninitialized. Since it is not used
otherwise, remove it.

Signed-off-by: Christoph Jaeger <christophjaeger@linux.com>
Signed-off-by: Mark Brown <broonie@linaro.org>