If the hub_configure() fails after setting the hdev->maxchild
the hub->ports might be NULL or point to uninitialized kzallocated
memory causing NULL pointer dereference in hub_quiesce() during cleanup.

Now after such error the hdev->maxchild is set to 0 to avoid cleanup
of uninitialized ports.
Signed-off-by: NKrzysztof Mazur <krzysiek@podlesie.net>
Acked-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>