usb: xhci: Free the right ring in xhci_add_endpoint()

usb: xhci: Free the right ring in xhci_add_endpoint()

commit 9821786d7c90eee2f6852261893d9703801aae47 upstream.

In the xhci_add_endpoint(), a new ring was allocated and saved at
xhci_virt_ep->new_ring. Hence, when error happens, we need to free
the allocated ring before returning error.

Current code frees xhci_virt_ep->ring instead of the new_ring. This
patch fixes this.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>