iio: accel: sca3300: fix uninitialized iio scan data

Fix potential leak of uninitialized stack data to userspace by ensuring
that the `channels` array is zeroed before use.

Fixes: edeb67f ("iio: accel: sca3300: use IIO_DECLARE_BUFFER_WITH_TS")
Signed-off-by: David Lechner <dlechner@baylibre.com>
Link: https://patch.msgid.link/20250723-iio-accel-sca3300-fix-uninitialized-iio-scan-data-v1-1-12dbfb3307b7@baylibre.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Author: dlech

drivers/iio/accel/sca3300.c

@@ -477,7 +477,7 @@ static irqreturn_t sca3300_trigger_handler(int irq, void *p)
 	struct iio_dev *indio_dev = pf->indio_dev;
 	struct sca3300_data *data = iio_priv(indio_dev);
 	int bit, ret, val, i = 0;
-	IIO_DECLARE_BUFFER_WITH_TS(s16, channels, SCA3300_SCAN_MAX);
+	IIO_DECLARE_BUFFER_WITH_TS(s16, channels, SCA3300_SCAN_MAX) = { };
 
 	iio_for_each_active_channel(indio_dev, bit) {
 		ret = sca3300_read_reg(data, indio_dev->channels[bit].address, &val);