Fix multiple bugs in LXC domainMemoryStats driver
Fix multiple bugs in LXC domainMemoryStats driver

The virCgroupXXX APIs' return value must be checked for
being less than 0, not equal to 0.

An VIR_ERR_OPERATION_INVALID error must also be raised
when the VM is not running to prevent a crash on NULL
priv->cgroup field.

Signed-off-by: Daniel P. Berrange <bb938cf255e055ff3507f2627d214e8e62118fcf@redhat.com>

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