Replace xhci_find_new_dequeue_state() and xhci_queue_new_dequeue_state()
functions with one combined function.
These function were always called after each other, and had a lot of extra
code just to pass the newly found dequeue state from the first function
to the other.

The new function also returns error in case there is a failure to
queue the new dequeue state. This way the caller can decide on
recovery measures to handle it.
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20210129130044.206855-25-mathias.nyman@linux.intel.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>