ASoC: wcd-mbhc-v2: remove useless initialization

cppcheck warning:

sound/soc/codecs/wcd-mbhc-v2.c:1309:17: style: Variable 'clamp_state'
is assigned a value that is never used. [unreadVariable]
 u8 clamp_state = 0;
                ^
Signed-off-by: NPierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: NBard Liao <yung-chuan.liao@linux.intel.com>
Reviewed-by: NPéter Ujfalusi <peter.ujfalusi@linux.intel.com>
Link: https://lore.kernel.org/r/20220520211719.607543-4-pierre-louis.bossart@linux.intel.comSigned-off-by: NMark Brown <broonie@kernel.org>

sound/soc/codecs/wcd-mbhc-v2.c

@@ -1306,7 +1306,7 @@ static irqreturn_t wcd_mbhc_adc_hs_rem_irq(int irq, void *data)
 static irqreturn_t wcd_mbhc_adc_hs_ins_irq(int irq, void *data)
 {
 	struct wcd_mbhc *mbhc = data;
-	u8 clamp_state = 0;
+	u8 clamp_state;
 	u8 clamp_retry = WCD_MBHC_FAKE_INS_RETRY;
 
 	/*