ASoC: rt5682: remove useless initialization

cppcheck complains about a possible null pointer dereference, but the
problem is rather an useless initialization before walking through a
list.
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20210302212527.55158-25-pierre-louis.bossart@linux.intel.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/codecs/rt5682.c

@@ -2751,7 +2751,7 @@ static int rt5682_bclk_set_rate(struct clk_hw *hw, unsigned long rate,
 		container_of(hw, struct rt5682_priv,
 			     dai_clks_hw[RT5682_DAI_BCLK_IDX]);
 	struct snd_soc_component *component = rt5682->component;
-	struct snd_soc_dai *dai = NULL;
+	struct snd_soc_dai *dai;
 	unsigned long factor;
 
 	if (!rt5682_clk_check(rt5682))