iio: adc: ad7476: remove redundant null check on an array

The null check on st->chip_info->convst_channel is redundant because
convst_channel is a 2 element array of struct iio_chan_spec objects
and this can never be null. Fix this by removing the null check.

Addresses-Coverity: ("Array compared against 0")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/adc/ad7476.c

@@ -309,7 +309,7 @@ static int ad7476_probe(struct spi_device *spi)
 	indio_dev->num_channels = 2;
 	indio_dev->info = &ad7476_info;
 
-	if (st->convst_gpio && st->chip_info->convst_channel)
+	if (st->convst_gpio)
 		indio_dev->channels = st->chip_info->convst_channel;
 	/* Setup default message */