usb: wusbcore: fix string formatting warnings on 64-bit builds

This patch fixes compile warnings on 64-bit builds that were introduced
by the recent isoc changes.

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Reported-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Thomas Pugliese <thomas.pugliese@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>