init: Adding give_up() method to exit if failing

If we do fail, we always need to setup a shell with a string explaining
what happened. give_up is made for that

 give_up <reason_of_giving_up>
init: Reporting avail network cards if none found

If no network card got detected by the kernel, let's inspect the pci bus
and report both name & PCI ids to understand what hardware is running
here.

This could help understanding if no network card is present or if it's a
lack of the kernel configuration or missing drivers