[PATCH] USB: Fix maxpacket length for ep0 on root hubs

This patch (as591) fixes a rather innocuous bug that has been around for
quite a long time: Virtual root hubs should have a maxpacket length of
64 for endpoint 0.  I didn't realize it was wrong until I started
looking through the endpoint attribute files.

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