iio: chemical: sgp30: Drop use of %hx in format string.

Since:
commit cbacb5ab ("docs: printk-formats: Stop encouraging use of
unnecessary %h[xudi] and %hh[xudi]")
use of these format strings has been discouraged.

As there are only a few such uses in IIO, lets clear them all out and
avoid chance of them getting copied into new drivers.
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Andreas Brauchli <andreas.brauchli@sensirion.com>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/r/20210517125554.1463156-5-jic23@kernel.org

drivers/iio/chemical/sgp30.c

@@ -425,7 +425,7 @@ static int sgp_check_compat(struct sgp_data *data,
 
 	product = SGP_VERS_PRODUCT(data);
 	if (product != product_id) {
-		dev_err(dev, "sensor reports a different product: 0x%04hx\n",
+		dev_err(dev, "sensor reports a different product: 0x%04x\n",
 			product);
 		return -ENODEV;
 	}