ASoC: amd: acp: delete unnecessary NULL check

The list iterator can't be NULL.  Delete the check and pull the code
in one tab.

Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Link: https://lore.kernel.org/r/b0c5b0ca-68da-47e6-a8b0-e0714f0de119@moroto.mountain


Signed-off-by: Mark Brown <broonie@kernel.org>