vfio-pci: Generalize setup of simple eventfds
vfio-pci: Generalize setup of simple eventfds

We want another single vector IRQ index to support signaling of
the device request to userspace.  Generalize the error reporting
IRQ index to avoid code duplication.

Signed-off-by: Alex Williamson <7469de9b95ba379e2656fa9677689657c47a7690@redhat.com>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs