test: Reuse virDomainObjGetOneDef in testDomainGetVcpusFlags
test: Reuse virDomainObjGetOneDef in testDomainGetVcpusFlags

The test driver copies the domain definition correctly so we can reuse
the helper.

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