Oh, too many input cases.

Below patch tries to recognize the following input:
pci = ['0001:02:03.4@5']
pci = ['0001:02:03.4']
pci = ['02:03.4@5']
pci = ['02:03.4']

Hope so.

Stefano Stabellini wrote:
>
> the test on the return value should be "< 5", otherwise it wouldn't work
> if you use
>
> pci = ['01:00.0@0']
>
>