ASoC: rockchip: simplify error handling

cppcheck warning:

sound/soc/rockchip/rk3288_hdmi_analog.c:256:9: warning: Identical
condition and return expression 'ret', return value is always 0
[identicalConditionAfterEarlyExit]
 return ret;
        ^
sound/soc/rockchip/rk3288_hdmi_analog.c:252:6: note: If condition
'ret' is true, the function will return/exit
 if (ret)
     ^
sound/soc/rockchip/rk3288_hdmi_analog.c:256:9: note: Returning
identical expression 'ret'
 return ret;
        ^

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Reviewed-by: Péter Ujfalusi <peter.ujfalusi@linux.intel.com>
Link: https://lore.kernel.org/r/20220520211719.607543-15-pierre-louis.bossart@linux.intel.com


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