usb: gadget: f_hid: use after free in hidg_alloc_inst()

We free "opts" on the error path and then dereference it.

Fixes: 21a9476 ('usb: gadget: hid: add configfs support')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

drivers/usb/gadget/function/f_hid.c

@@ -875,6 +875,7 @@ static struct usb_function_instance *hidg_alloc_inst(void)
 		kfree(opts);
 		if (idr_is_empty(&hidg_ida.idr))
 			ghid_cleanup();
+		goto unlock;
 	}
 	config_group_init_type_name(&opts->func_inst.group, "", &hid_func_type);