ASoC: mt6359: remove useless assignment

ASoC: mt6359: remove useless assignment

cppcheck warning:

sound/soc/codecs/mt6359.c:242:19: style: Variable 'stage' is assigned a value that is never used. [unreadVariable]
 int i = 0, stage = 0;
                  ^
sound/soc/codecs/mt6359.c:260:19: style: Variable 'stage' is assigned a value that is never used. [unreadVariable]
 int i = 0, stage = 0;
                  ^
sound/soc/codecs/mt6359.c:274:8: style: Variable 'i' is assigned a value that is never used. [unreadVariable]
 int i = 0, stage = 0;
       ^
sound/soc/codecs/mt6359.c:274:19: style: Variable 'stage' is assigned a value that is never used. [unreadVariable]
 int i = 0, stage = 0;
                  ^

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20210312182246.5153-15-pierre-louis.bossart@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>