[PATCH] USB: optimise devio.c usbdev_read fix

drivers/usb/core/devio.c: In function `usbdev_read':
drivers/usb/core/devio.c:140: error: invalid type argument of `->'
drivers/usb/core/devio.c:141: error: invalid type argument of `->'
drivers/usb/core/devio.c:142: error: invalid type argument of `->'
drivers/usb/core/devio.c:143: error: invalid type argument of `->'

Cc: Oliver Neukum <oliver@neukum.org>
Cc: Pete Zaitcev <zaitcev@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>