Comment 5 for bug 1649464

Thanks to Scott for showing me a device with those symptoms.
(it's a server using desktop Ubuntu image)

Current situation
-----------------

$ ./graphics_card_resource -c ./udev_resource
Traceback (most recent call last):
  File "./graphics_card_resource", line 168, in <module>
    raise SystemExit(main())
  File "./graphics_card_resource", line 122, in main
    video_devices.sort(key=lambda r: bus_ordering(r))
  File "./graphics_card_resource", line 122, in <lambda>
    video_devices.sort(key=lambda r: bus_ordering(r))
  File "./graphics_card_resource", line 97, in bus_ordering
    return int(record.get('path').split(':')[-2])
ValueError: invalid literal for int() with base 10: 'b3'

Root cause
----------

So far, the digit extracted by bus_ordering() had always been a base 10 integer.
However, on servers, the extracted digit looks more like an hexadecimal value (base 16 integer):

/devices/pci0000:b2/0000:b2:00.0/0000:b3:00.0

Solution
--------

In /usr/lib/plainbox-provider-resource-generic/bin/graphics_card_resource, line 96, replace:

    return int(record.get('path').split(':')[-2])

with:

    return int(record.get('path').split(':')[-2], 16)

Result
------

$ ./graphics_card_resource -c ./udev_resource
bus: pci
category: VIDEO
driver: nvidia
index: 1
path: /devices/pci0000:b2/0000:b2:00.0/0000:b3:00.0
prime_gpu_offload: Off
product: PCI ID 0x1cb1
product_id: 7345
product_slug: PCI_ID_0x1cb1
subproduct_id: 4540
subvendor_id: 4136
vendor: NVIDIA Corporation
vendor_id: 4318
vendor_slug: NVIDIA_Corporation

This change should not create regression, but it has to be confirmed by testing on a laptop/desktop before pushing to stable.