USB: address-0 handling during device initialization

This patch (as947) changes the device initialization and enumeration
code in hub.c; now udev->devnum will be set to 0 while the device is
being accessed at address 0.  Until now this wasn't needed because the
address value was passed as part of urb->pipe; without that field the
device address must be stored elsewhere.

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