USB HID: remove some compiler warnings

drivers/usb/input/hid-debug.h

@@ -345,7 +345,7 @@ static void hid_dump_field(struct hid_field *field, int n) {
 	printk(")\n");
 }
 
-static void hid_dump_device(struct hid_device *device) {
+static void __attribute__((unused)) hid_dump_device(struct hid_device *device) {
 	struct hid_report_enum *report_enum;
 	struct hid_report *report;
 	struct list_head *list;
@@ -379,7 +379,7 @@ static void hid_dump_device(struct hid_device *device) {
 	}
 }
 
-static void hid_dump_input(struct hid_usage *usage, __s32 value) {
+static void __attribute__((unused)) hid_dump_input(struct hid_usage *usage, __s32 value) {
 	printk("hid-debug: input ");
 	resolv_usage(usage->hid);
 	printk(" = %d\n", value);