[libvirt] [PATCH 0/2] qemu: make PCI multifunction support more manual

Problems have been encountered/realized with the practice of unconditionally setting the multifunction bit for all functions of all devices. PATCH 2/2 remedies that (details in its own commit comment). PATCH 1/2 is a one-liner I fixed in the meantime which will cause a simple conflict if it's not applied to other branches at the same time as PATCH 2/2, so I'm sending them together.