ASoC: cs42l52: fix the return value of cs42l52_set_fmt()

Fix the return value of cs42l52_set_fmt() when clock inversion is
not allowed and also remove the useless variable ret.

dpatch engine is used to auto generate this patch.
(https://github.com/weiyj/dpatch)

[We had been assigning to ret but then ignoring the value we assgined
-- broonie]

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: stable@vger.kernel.org