According to the official Marshmallow permissions video (at the 4m 43s mark), you must open the application Settings page instead (from there it is one click to the Permissions page).
To open the settings page, you would do
Intent intent = new Intent(Settings.ACTION_APPLICATION_DETAILS_SETTINGS);
Uri uri = Uri.fromParts("package", getPackageName(), null);
intent.setData(uri);
startActivity(intent);