iio: bmc150-accel-core: 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/b1b0d662705b43d68594639fb7719bc431101f79.1664782676.git.mazziesaccount@gmail.comSigned-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/accel/bmc150-accel-core.c

@@ -925,22 +925,9 @@ static const struct iio_chan_spec_ext_info bmc150_accel_ext_info[] = {
 	{ }
 };
 
-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(BMC150_ACCEL_FIFO_LENGTH));
-}
-
-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(BMC150_ACCEL_FIFO_LENGTH));
 static IIO_DEVICE_ATTR(hwfifo_enabled, S_IRUGO,
 		       bmc150_accel_get_fifo_state, NULL, 0);
 static IIO_DEVICE_ATTR(hwfifo_watermark, S_IRUGO,