ASoC: lm49453: fix useless assignment before return

Cppcheck warning:

sound/soc/codecs/lm49453.c:1210:11: style: Variable 'pll_clk' is
assigned a value that is never used. [unreadVariable]

  pll_clk = BIT(4);
          ^

FIXME: What is the correct fix?
	/* fll clk slection */
	pll_clk = BIT(4);
	return 0;

is the assignment redundant or the 'return 0' a mistake?
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20210326221619.949961-2-pierre-louis.bossart@linux.intel.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/codecs/lm49453.c

@@ -1206,8 +1206,6 @@ static int lm49453_set_dai_sysclk(struct snd_soc_dai *dai, int clk_id,
 		break;
 	case 48000:
 	case 32576:
-		/* fll clk slection */
-		pll_clk = BIT(4);
 		return 0;
 	default:
 		return -EINVAL;