lxc: fix starting a domain with a cpuset but no numatune
lxc: fix starting a domain with a cpuset but no numatune

 # virsh -c lxc:/// start helloworld
 error: Failed to start domain helloworld
 error: internal error: guest failed to start: Invalid value '1-3'
 for 'cpuset.mems': Invalid argument

Free the cpu mask to avoid reusing it as a mem mask
in virCgroupSetCpusetMems
if virDomainNumatuneMaybeFormatNodeset does not set a mask.

Signed-off-by: Luyao Huang <23d9981432efa88691fd2a71f5525bc2174f7664@redhat.com>
Signed-off-by: Ján Tomko <4cab11cfb98d3c937327354a78eb07dbb6ee2bc6@redhat.com>

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