[PATCH] USB: Fix regression in core/devio.c

This patch (as551) fixes another little problem recently added to the
USB core.  Someone didn't fix the type of the first argument to
unregister_chrdev_region.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>