staging: iio: adis16240_core: Replace symbolic permission with octal permission

The patch resolves following checkpatch issue:
WARNING: Symbolic permissions 'S_IRUGO' are not preferred. Consider using
octal permissions '0444'.
Signed-off-by: sayli karnik <karniksayli1995@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

drivers/staging/iio/accel/adis16240_core.c

@@ -65,7 +65,7 @@ static ssize_t adis16240_read_12bit_signed(struct device *dev,
 	return ret;
 }
 
-static IIO_DEVICE_ATTR(in_accel_xyz_squared_peak_raw, S_IRUGO,
+static IIO_DEVICE_ATTR(in_accel_xyz_squared_peak_raw, 0444,
 		       adis16240_read_12bit_signed, NULL,
 		       ADIS16240_XYZPEAK_OUT);