iio: adxl367: Use IIO_STATIC_CONST_DEVICE_ATTR()

Slightly simplify by dropping open-coded constant data iio_dev_attr
functions and using the IIO_STATIC_CONST_DEVICE_ATTR() instead.
Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com>
Link: https://lore.kernel.org/r/c96c55363b8f36017ef7f18fdfe810cd3990e2a4.1664782676.git.mazziesaccount@gmail.comSigned-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/accel/adxl367.c

@@ -1183,22 +1183,9 @@ static ssize_t adxl367_get_fifo_watermark(struct device *dev,
 	return sysfs_emit(buf, "%d\n", fifo_watermark);
 }
 
-static ssize_t hwfifo_watermark_min_show(struct device *dev,
-					 struct device_attribute *attr,
-					 char *buf)
-{
-	return sysfs_emit(buf, "%s\n", "1");
-}
-
-static ssize_t hwfifo_watermark_max_show(struct device *dev,
-					 struct device_attribute *attr,
-					 char *buf)
-{
-	return sysfs_emit(buf, "%s\n", __stringify(ADXL367_FIFO_MAX_WATERMARK));
-}
-
-static IIO_DEVICE_ATTR_RO(hwfifo_watermark_min, 0);
-static IIO_DEVICE_ATTR_RO(hwfifo_watermark_max, 0);
+IIO_STATIC_CONST_DEVICE_ATTR(hwfifo_watermark_min, "1");
+IIO_STATIC_CONST_DEVICE_ATTR(hwfifo_watermark_max,
+			     __stringify(ADXL367_FIFO_MAX_WATERMARK));
 static IIO_DEVICE_ATTR(hwfifo_watermark, 0444,
 		       adxl367_get_fifo_watermark, NULL, 0);
 static IIO_DEVICE_ATTR(hwfifo_enabled, 0444,