HID: huawei: fix missing hid_is_usb() check

In the Linux kernel, the following vulnerability has been resolved: HID: huawei: fix missing hid_is_usb() check to_usb_interface() can only be used on a hid_device whose parent is really USB; uhid can create devices that identify as being on BUS_USB, but don't actually have a USB parent. Fix the use of to_usb_interface() without a hid_is_usb() check. I have verified that it is currently possible to trigger a kernel splat due to this bug in an ASAN build, and that this commit fixes the issue.