xhci: cleanup finish_td() skip option

finish_td() could be called with a skip option to bypass most of the
function and only call xhci_td_cleanup() at the end.

Remove this skip option and call xhci_td_cleanup() directly instead
when needed

No functional changes

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