platform/chrome: cros_ec: Fix leak in sequence_store()

The allocated cros_ec_command message structure is not freed in function
sequence_store(). Make sure that 'msg' is freed in all exit paths.
Detected by Coverity CID 1309667.
Signed-off-by: Christian Engelmayer <cengelma@gmx.at>
Signed-off-by: Olof Johansson <olof@lixom.net>

drivers/platform/chrome/cros_ec_lightbar.c

@@ -352,10 +352,6 @@ static ssize_t sequence_store(struct device *dev, struct device_attribute *attr,
 	struct cros_ec_dev *ec = container_of(dev,
 					      struct cros_ec_dev, class_dev);
 
-	msg = alloc_lightbar_cmd_msg(ec);
-	if (!msg)
-		return -ENOMEM;
-
 	for (len = 0; len < count; len++)
 		if (!isalnum(buf[len]))
 			break;
@@ -370,21 +366,30 @@ static ssize_t sequence_store(struct device *dev, struct device_attribute *attr,
 			return ret;
 	}
 
+	msg = alloc_lightbar_cmd_msg(ec);
+	if (!msg)
+		return -ENOMEM;
+
 	param = (struct ec_params_lightbar *)msg->data;
 	param->cmd = LIGHTBAR_CMD_SEQ;
 	param->seq.num = num;
 	ret = lb_throttle();
 	if (ret)
-		return ret;
+		goto exit;
 
 	ret = cros_ec_cmd_xfer(ec->ec_dev, msg);
 	if (ret < 0)
-		return ret;
+		goto exit;
 
-	if (msg->result != EC_RES_SUCCESS)
-		return -EINVAL;
+	if (msg->result != EC_RES_SUCCESS) {
+		ret = -EINVAL;
+		goto exit;
+	}
 
-	return count;
+	ret = count;
+exit:
+	kfree(msg);
+	return ret;
 }
 
 /* Module initialization */