usb: xhci-mtk: fix leakage of shared hcd when fail to set wakeup irq

In the Linux kernel, the following vulnerability has been resolved: usb: xhci-mtk: fix leakage of shared hcd when fail to set wakeup irq Can not set the @shared_hcd to NULL before decrease the usage count by usb_put_hcd(), this will cause the shared hcd not released.