usb: wusbcore: fix stranded URB after HWA unplug

This patch adds error checking to the abort request callback to forcibly
clean up the dequeued transfers if the abort request failed.  The
wa_complete_remaining_xfer_segs was modified so that it could be used in
this situation as well.  This fixes a stranded URB/PNP hang when the HWA
is unplugged while playing audio to a wireless audio device.

Signed-off-by: Thomas Pugliese <thomas.pugliese@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>