iio: accel: hid: Fix buffer alignment in iio_push_to_buffers_with_timestamp()

To make code more readable, use a structure to express the channel
layout and ensure the timestamp is 8 byte aligned.
Note this matches what was done in all the other hid sensor drivers.
This one was missed previously due to an extra level of indirection.

Found during an audit of all calls of this function.

Fixes: a96cd0f9 ("iio: accel: hid-sensor-accel-3d: Add timestamp")
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20210501170121.512209-4-jic23@kernel.org

drivers/iio/accel/hid-sensor-accel-3d.c

@@ -28,8 +28,11 @@ struct accel_3d_state {
 	struct hid_sensor_hub_callbacks callbacks;
 	struct hid_sensor_common common_attributes;
 	struct hid_sensor_hub_attribute_info accel[ACCEL_3D_CHANNEL_MAX];
-	/* Reserve for 3 channels + padding + timestamp */
-	u32 accel_val[ACCEL_3D_CHANNEL_MAX + 3];
+	/* Ensure timestamp is naturally aligned */
+	struct {
+		u32 accel_val[3];
+		s64 timestamp __aligned(8);
+	} scan;
 	int scale_pre_decml;
 	int scale_post_decml;
 	int scale_precision;
@@ -245,8 +248,8 @@ static int accel_3d_proc_event(struct hid_sensor_hub_device *hsdev,
 			accel_state->timestamp = iio_get_time_ns(indio_dev);
 
 		hid_sensor_push_data(indio_dev,
-				     accel_state->accel_val,
-				     sizeof(accel_state->accel_val),
+				     &accel_state->scan,
+				     sizeof(accel_state->scan),
 				     accel_state->timestamp);
 
 		accel_state->timestamp = 0;
@@ -271,7 +274,7 @@ static int accel_3d_capture_sample(struct hid_sensor_hub_device *hsdev,
 	case HID_USAGE_SENSOR_ACCEL_Y_AXIS:
 	case HID_USAGE_SENSOR_ACCEL_Z_AXIS:
 		offset = usage_id - HID_USAGE_SENSOR_ACCEL_X_AXIS;
-		accel_state->accel_val[CHANNEL_SCAN_INDEX_X + offset] =
+		accel_state->scan.accel_val[CHANNEL_SCAN_INDEX_X + offset] =
 						*(u32 *)raw_data;
 		ret = 0;
 	break;