Instead of passing slot id and endpoint index to
cleanup_halted_endpoint() pass the endpoint structure pointer
as it's already known.

Avoids again digging out the endpoint structure based on
slot id and endpoint index, and passing them along the
call chain for this purpose only.

Add slot_id to the virt_dev structure so that it
can easily be found from a virt_dev, or its child, the
virt_ep endpoint structure.
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20210129130044.206855-4-mathias.nyman@linux.intel.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>