iio: light: si1133: fix uninitialized resp variable

Read response register to detect any error.
Signed-off-by: Maxime Roussin-Bélanger <maxime.roussinbelanger@gmail.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/light/si1133.c

@@ -409,6 +409,9 @@ static int si1133_command(struct si1133_data *data, u8 cmd)
 			err = -ETIMEDOUT;
 			goto out;
 		}
+		err = regmap_read(data->regmap, SI1133_REG_RESPONSE0, &resp);
+		if (err)
+			goto out;
 	} else {
 		err = regmap_read_poll_timeout(data->regmap,
 					       SI1133_REG_RESPONSE0, resp,