[PATCH] ASoC: dapm: Add missing mutex unlock

[Charles Keepax <ckeepax@opensource.wolfsonmicro.com>]

The is a missing mutex unlock on the error path in
snd_soc_dapm_get_enum_double. This was introduced in commit
561ed680b764 ("ASoC: dapm: Add support for autodisable mux controls").
This patch adds the missing unlock.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
---
 sound/soc/soc-dapm.c |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)

diff --git a/sound/soc/soc-dapm.c b/sound/soc/soc-dapm.c
index ea3348e..6374852 100644
--- a/sound/soc/soc-dapm.c
+++ b/sound/soc/soc-dapm.c
@@ -3075,8 +3075,10 @@ int snd_soc_dapm_get_enum_double(struct snd_kcontrol *kcontrol,
 	mutex_lock_nested(&card->dapm_mutex, SND_SOC_DAPM_CLASS_RUNTIME);
 	if (e->reg != SND_SOC_NOPM && dapm_kcontrol_is_powered(kcontrol)) {
 		int ret = soc_dapm_read(dapm, e->reg, &reg_val);
-		if (ret)
+		if (ret) {
+			mutex_unlock(&card->dapm_mutex);
 			return ret;
+		}
 	} else {
 		reg_val = dapm_kcontrol_get_value(kcontrol);
 	}
-- 
1.7.2.5