hwmon: (amc6821) Double unlock bug

The mutex gets unlocked after we goto EXIT.

Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
diff --git a/drivers/hwmon/amc6821.c b/drivers/hwmon/amc6821.c
index 1c89d92..fa9708c 100644
--- a/drivers/hwmon/amc6821.c
+++ b/drivers/hwmon/amc6821.c
@@ -686,7 +686,6 @@
 		data->fan1_div = 4;
 		break;
 	default:
-		mutex_unlock(&data->update_lock);
 		count = -EINVAL;
 		goto EXIT;
 	}