USB: update of Documentation/usb/anchors.txt

are called in the reverse temporal order they were submitted.

This way no data can be reordered.

usb_unlink_anchored_urbs()

--------------------------

This function unlinks all URBs associated with an anchor. The URBs

are processed in the reverse temporal order they were submitted.

This is similar to usb_kill_anchored_urbs(), but it will not sleep.

Therefore no guarantee is made that the URBs have been unlinked when

the call returns. They may be unlinked later but will be unlinked in

finite time.

usb_wait_anchor_empty_timeout()

-------------------------------

This function waits for all URBs associated with an anchor to finish

or a timeout, whichever comes first. Its return value will tell you

whether the timeout was reached.