iio: gyro: check sscanf return value

This patch fixes the checkpatch warnings:
WARNING: unchecked sscanf return value
Signed-off-by: Ioana Ciornei <ciorneiioana@gmail.com>
Acked-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

drivers/iio/gyro/adis16136.c

@@ -435,7 +435,9 @@ static int adis16136_initial_setup(struct iio_dev *indio_dev)
 	if (ret)
 		return ret;
 
-	sscanf(indio_dev->name, "adis%u\n", &device_id);
+	ret = sscanf(indio_dev->name, "adis%u\n", &device_id);
+	if (ret != 1)
+		return -EINVAL;
 
 	if (prod_id != device_id)
 		dev_warn(&indio_dev->dev, "Device ID(%u) and product ID(%u) do not match.",