USB: convert away from urb->status in xpad driver

USB is moving to transfering status as a parameter. To ease the transition
urb->status is to be touched only once in a function. The xpad driver has
been overlooked. Dmitry wants this to go through the USB tree.

Signed-off-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>