drivers/hid/hid-lg4ff.c: avoid world-writable sysfs files.

In line with practice for module parameters, we're adding a build-time
check that sysfs files aren't world-writable.

Cc: Simon Wood <simon@mungewell.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

drivers/hid/hid-lg4ff.c

@@ -52,7 +52,7 @@ static void hid_lg4ff_set_range_g25(struct hid_device *hid, u16 range);
 static ssize_t lg4ff_range_show(struct device *dev, struct device_attribute *attr, char *buf);
 static ssize_t lg4ff_range_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count);
 
-static DEVICE_ATTR(range, S_IRWXU | S_IRWXG | S_IRWXO, lg4ff_range_show, lg4ff_range_store);
+static DEVICE_ATTR(range, S_IRWXU | S_IRWXG | S_IROTH, lg4ff_range_show, lg4ff_range_store);
 
 struct lg4ff_device_entry {
 	__u32 product_id;