ASoC: Fix return value of ak4641_pcm_set_dai_fmt()

We can't just pass back the return value of snd_soc_update_bits() as it
will be 1 if a bit changed rather than zero.

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
diff --git a/sound/soc/codecs/ak4641.c b/sound/soc/codecs/ak4641.c
index 266ebea..c4d165a 100644
--- a/sound/soc/codecs/ak4641.c
+++ b/sound/soc/codecs/ak4641.c
@@ -339,6 +339,7 @@
 {
 	struct snd_soc_codec *codec = codec_dai->codec;
 	u8 btif;
+	int ret;
 
 	/* interface format */
 	switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
@@ -358,7 +359,11 @@
 		return -EINVAL;
 	}
 
-	return snd_soc_update_bits(codec, AK4641_BTIF, (0x3 << 5), btif);
+	ret = snd_soc_update_bits(codec, AK4641_BTIF, (0x3 << 5), btif);
+	if (ret < 0)
+		return ret;
+
+	return 0;
 }
 
 static int ak4641_i2s_set_dai_fmt(struct snd_soc_dai *codec_dai,