USB: appletouch: fix atp_disconnect

appletouch uses urb->transfer_dma after having freed the urb, this shows
up only if the system is compiled with slab debugging. This patch fixes
it by reordering the free calls.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Vojtech Pavlik <vojtech@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>