ASoC: tda7419: use true and false for boolean values

Return statements in functions returning bool should use true or false
instead of an integer value.

This code was detected with the help of Coccinelle.
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/codecs/tda7419.c

@@ -142,9 +142,9 @@ struct tda7419_vol_control {
 static inline bool tda7419_vol_is_stereo(struct tda7419_vol_control *tvc)
 {
 	if (tvc->reg == tvc->rreg)
-		return 0;
+		return false;
 
-	return 1;
+	return true;
 }
 
 static int tda7419_vol_info(struct snd_kcontrol *kcontrol,