Fix qemu-nbd cleanup crashes
Fix qemu-nbd cleanup crashes

The virLXCControllerAppendNBDPids function didn't properly initialize
pids and npids. In case of failure it was crashing when freeing those.

taget/libvirt,nertpinx/libvirt,VenkatDatta/libvirt,rlaager/libvirt,jfehlig/libvirt,fabianfreyer/libvirt,olafhering/libvirt,datto/libvirt,crobinso/libvirt,rlaager/libvirt,agx/libvirt,eskultety/libvirt,zippy2/libvirt,eskultety/libvirt,libvirt/libvirt,olafhering/libvirt,agx/libvirt,eskultety/libvirt,datto/libvirt,taget/libvirt,fabianfreyer/libvirt,VenkatDatta/libvirt,andreabolognani/libvirt,crobinso/libvirt,rlaager/libvirt,datto/libvirt,andreabolognani/libvirt,jardasgit/libvirt,VenkatDatta/libvirt,zippy2/libvirt,datto/libvirt,nertpinx/libvirt,olafhering/libvirt,nertpinx/libvirt,jfehlig/libvirt,datto/libvirt,libvirt/libvirt,jfehlig/libvirt,zippy2/libvirt,libvirt/libvirt,jardasgit/libvirt,VenkatDatta/libvirt,jardasgit/libvirt,eskultety/libvirt,VenkatDatta/libvirt,nertpinx/libvirt,taget/libvirt,fabianfreyer/libvirt,nertpinx/libvirt,rlaager/libvirt,libvirt/libvirt,taget/libvirt,andreabolognani/libvirt,fabianfreyer/libvirt,jfehlig/libvirt,agx/libvirt,agx/libvirt,olafhering/libvirt,andreabolognani/libvirt,crobinso/libvirt,crobinso/libvirt,andreabolognani/libvirt,taget/libvirt,zippy2/libvirt,agx/libvirt,jardasgit/libvirt,rlaager/libvirt,jardasgit/libvirt,fabianfreyer/libvirt,eskultety/libvirt