iio: accel: kionix-kx022a: Get the timestamp from the driver's private data in the trigger_handler

The trigger_handler gets called from the IRQ thread handler using
iio_trigger_poll_chained() which will only call the bottom half of the
pollfunc and therefore pf->timestamp will not get set.

Use instead the timestamp from the driver's private data which is always
set in the IRQ handler.

Fixes: 7c1d1677 ("iio: accel: Support Kionix/ROHM KX022A accelerometer")
Link: https://lore.kernel.org/linux-iio/Y+6QoBLh1k82cJVN@carbian/Reviewed-by: Matti Vaittinen <mazziesaccount@gmail.com>
Signed-off-by: Mehdi Djait <mehdi.djait.k@gmail.com>
Link: https://lore.kernel.org/r/20230218135111.90061-1-mehdi.djait.k@gmail.com
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/accel/kionix-kx022a.c

@@ -864,7 +864,7 @@ static irqreturn_t kx022a_trigger_handler(int irq, void *p)
 	if (ret < 0)
 		goto err_read;
 
-	iio_push_to_buffers_with_timestamp(idev, data->buffer, pf->timestamp);
+	iio_push_to_buffers_with_timestamp(idev, data->buffer, data->timestamp);
 err_read:
 	iio_trigger_notify_done(idev->trig);