cppcheck complains, use separate loop variable for sink and source ports

sound/soc/codecs/rt711-sdw.c:382:4: style: Variable 'i' is reassigned
a value before the old one has been used. [redundantAssignment]
 i = 0;
   ^
sound/soc/codecs/rt711-sdw.c:371:4: note: i is assigned
  i++;
   ^
sound/soc/codecs/rt711-sdw.c:382:4: note: i is overwritten
 i = 0;
   ^
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Reviewed-by: Rander Wang <rander.wang@linux.intel.com>
Link: https://lore.kernel.org/r/20201111214318.150529-4-pierre-louis.bossart@linux.intel.comSigned-off-by: Mark Brown <broonie@kernel.org>