iio: proximity: lidar: correct return value

lidar_i2c_xfer() function was never a non-positive value on error,
and this correct that with a -EIO return code.

Fixes: 366e65633cf4 ("iio: proximity: lidar: optimize i2c transactions")
Signed-off-by: Matt Ranostay <mranostay@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

drivers/iio/proximity/pulsedlight-lidar-lite-v2.c

@@ -87,7 +87,7 @@ static int lidar_i2c_xfer(struct lidar_data *data, u8 reg, u8 *val, int len)
 
 	ret = i2c_transfer(client->adapter, msg, 2);
 
-	return (ret == 2) ? 0 : ret;
+	return (ret == 2) ? 0 : -EIO;
 }
 
 static int lidar_smbus_xfer(struct lidar_data *data, u8 reg, u8 *val, int len)