usb: xhci: Remove ep_trb from finish_td()

Function argument ep_trb for finish_td() isn't needed anymore.
Cleanup it.

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>