iio: vcnl4000: Fix i2c swapped word reading.

[ Upstream commit 18dfb5326370991c81a6d1ed6d1aeee055cb8c05 ]

The bytes returned by the i2c reading need to be swapped
unconditionally. Otherwise, on be16 platforms, an incorrect value will be
returned.

Taking the slow path via next merge window as its been around a while
and we have a patch set dependent on this which would be held up.

Fixes: 62a1efb9f868 ("iio: add vcnl4000 combined ALS and proximity sensor")
Signed-off-by: Mathieu Othacehe <m.othacehe@gmail.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
diff --git a/drivers/iio/light/vcnl4000.c b/drivers/iio/light/vcnl4000.c
index 360b6e9..5a3a532 100644
--- a/drivers/iio/light/vcnl4000.c
+++ b/drivers/iio/light/vcnl4000.c
@@ -61,7 +61,6 @@ static int vcnl4000_measure(struct vcnl4000_data *data, u8 req_mask,
 				u8 rdy_mask, u8 data_reg, int *val)
 {
 	int tries = 20;
-	__be16 buf;
 	int ret;
 
 	mutex_lock(&data->lock);
@@ -88,13 +87,12 @@ static int vcnl4000_measure(struct vcnl4000_data *data, u8 req_mask,
 		goto fail;
 	}
 
-	ret = i2c_smbus_read_i2c_block_data(data->client,
-		data_reg, sizeof(buf), (u8 *) &buf);
+	ret = i2c_smbus_read_word_swapped(data->client, data_reg);
 	if (ret < 0)
 		goto fail;
 
 	mutex_unlock(&data->lock);
-	*val = be16_to_cpu(buf);
+	*val = ret;
 
 	return 0;