ASoC: tlv320aic3x - fix variable may be used uninitialized warning

If aic3x_read failed , val is used uninitialized.
Fix it by initializing val to 0.

This patch fixes below compile warning:
sound/soc/codecs/tlv320aic3x.c: In function 'aic3x_get_gpio':
sound/soc/codecs/tlv320aic3x.c:1183: warning: 'val' may be used uninitialized in this function
sound/soc/codecs/tlv320aic3x.c: In function 'aic3x_headset_detected':
sound/soc/codecs/tlv320aic3x.c:1211: warning: 'val' may be used uninitialized in this function
sound/soc/codecs/tlv320aic3x.c: In function 'aic3x_button_pressed':
sound/soc/codecs/tlv320aic3x.c:1219: warning: 'val' may be used uninitialized in this function

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Acked-by: Liam Girdwood <lrg@slimlogic.co.uk>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

sound/soc/codecs/tlv320aic3x.c

@@ -1176,7 +1176,7 @@ EXPORT_SYMBOL_GPL(aic3x_set_gpio);
 int aic3x_get_gpio(struct snd_soc_codec *codec, int gpio)
 {
 	u8 reg = gpio ? AIC3X_GPIO2_REG : AIC3X_GPIO1_REG;
-	u8 val, bit = gpio ? 2: 1;
+	u8 val = 0, bit = gpio ? 2 : 1;
 
 	aic3x_read(codec, reg, &val);
 	return (val >> bit) & 1;
@@ -1204,7 +1204,7 @@ EXPORT_SYMBOL_GPL(aic3x_set_headset_detection);
 
 int aic3x_headset_detected(struct snd_soc_codec *codec)
 {
-	u8 val;
+	u8 val = 0;
 	aic3x_read(codec, AIC3X_HEADSET_DETECT_CTRL_B, &val);
 	return (val >> 4) & 1;
 }
@@ -1212,7 +1212,7 @@ EXPORT_SYMBOL_GPL(aic3x_headset_detected);
 
 int aic3x_button_pressed(struct snd_soc_codec *codec)
 {
-	u8 val;
+	u8 val = 0;
 	aic3x_read(codec, AIC3X_HEADSET_DETECT_CTRL_B, &val);
 	return (val >> 5) & 1;
 }