[libvirt] UML driver struct refers to public API functions

Hi, The commit "Generic shared impls of all NUMA apis" (b0b968efd56f6c66bfa23eebbecd491ea993f99b) changed the UML driver struct to use the shared NUMA API. But now the UML driver struct refers to the public API functions: virNodeGetCellsFreeMemory virNodeGetFreeMemory instead of the shared NUMA API functions nodeGetCellsFreeMemory nodeGetFreeMemory This results in an infinite recursion, if someone's going to call virNodeGetCellsFreeMemory with an UML connection. Matthias