iio: prox: isl29501: Fix buffer alignment in iio_push_to_buffers_with_timestamp()

Add __aligned(8) to ensure the buffer passed to
iio_push_to_buffers_with_timestamp() is suitable for the naturally
aligned timestamp that will be inserted.

Here an explicit structure is not used, because the holes would
necessitate the addition of an explict memset(), to avoid a kernel
data leak, making for a less minimal fix.

Fixes: 1c287992 ("iio: light: isl29501: Add support for the ISL29501 ToF sensor.")
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Mathieu Othacehe <m.othacehe@gmail.com>
Reviewed-by: Nuno Sá <nuno.sa@analog.com>
Link: https://lore.kernel.org/r/20210613152301.571002-9-jic23@kernel.org

drivers/iio/proximity/isl29501.c

@@ -938,7 +938,7 @@ static irqreturn_t isl29501_trigger_handler(int irq, void *p)
 	struct iio_dev *indio_dev = pf->indio_dev;
 	struct isl29501_private *isl29501 = iio_priv(indio_dev);
 	const unsigned long *active_mask = indio_dev->active_scan_mask;
-	u32 buffer[4] = {}; /* 1x16-bit + ts */
+	u32 buffer[4] __aligned(8) = {}; /* 1x16-bit + naturally aligned ts */
 
 	if (test_bit(ISL29501_DISTANCE_SCAN_INDEX, active_mask))
 		isl29501_register_read(isl29501, REG_DISTANCE, buffer);