domain_conf: Free temporary variable
domain_conf: Free temporary variable

* src/conf/domain_conf.c: caller must free returned value of
  virXPathString in useserial

cbosdo/libvirt,siboulet/libvirt-openvz,elmarco/libvirt,shugaoye/libvirt,nertpinx/libvirt,VenkatDatta/libvirt,VenkatDatta/libvirt,jardasgit/libvirt,andreabolognani/libvirt,usc-isi/libvirt,crobinso/libvirt,novel/fbsd-libvirt,iam-TJ/libvirt,agx/libvirt,iam-TJ/libvirt,rmarwaha/libvirt1,novel/fbsd-libvirt,emaste/libvirt,emaste/libvirt,emaste/libvirt,zhlcindy/libvirt-1.1.4-maintain,dumbbell/libvirt,trainstack/libvirt,rmarwaha/libvirt1,iam-TJ/libvirt,jeckersb/libvirt,iam-TJ/libvirt,zhlcindy/libvirt-1.1.4-maintain,fabianfreyer/libvirt,warewolf/libvirt,VenkatDatta/libvirt,wiedi/libvirt,elmarco/libvirt,wiedi/libvirt,jeckersb/libvirt,zhlcindy/libvirt-1.1.4-maintain,agx/libvirt,danwent/libvirt-ovs,datto/libvirt,fabianfreyer/libvirt,siboulet/libvirt-openvz,leilihh/libvirt,zippy2/libvirt,taget/libvirt,jardasgit/libvirt,foomango/libvirt,olafhering/libvirt,novel/fbsd-libvirt,usc-isi/libvirt,zhlcindy/libvirt-1.1.4-maintain,trainstack/libvirt,jeckersb/libvirt,kantai/libvirt-vfork,andreabolognani/libvirt,nertpinx/libvirt,taget/libvirt,warewolf/libvirt,siboulet/libvirt-openvz,siboulet/libvirt-openvz,soulxu/libvirt-xuhj,rmarwaha/libvirt,usc-isi/libvirt,wiedi/libvirt,soulxu/libvirt-xuhj,trainstack/libvirt,wiedi/libvirt,jfehlig/libvirt,datto/libvirt,soulxu/libvirt-xuhj,jeckersb/libvirt,iam-TJ/libvirt,dumbbell/libvirt,fabianfreyer/libvirt,bjzhang/libvirt,kantai/libvirt-vfork,bjzhang/libvirt,zhlcindy/libvirt-1.1.4-maintain,rmarwaha/libvirt1,zippy2/libvirt,dumbbell/libvirt,fabianfreyer/libvirt,libvirt/libvirt,olafhering/libvirt,novel/fbsd-libvirt,soulxu/libvirt-xuhj,rmarwaha/libvirt1,cbosdo/libvirt,eskultety/libvirt,eskultety/libvirt,leilihh/libvirt,rmarwaha/libvirt,foomango/libvirt,wiedi/libvirt,novel/fbsd-libvirt,iam-TJ/libvirt,shugaoye/libvirt,nertpinx/libvirt,jardasgit/libvirt,jeckersb/libvirt,datto/libvirt,trainstack/libvirt,leilihh/libvirt,warewolf/libvirt,emaste/libvirt,kantai/libvirt-vfork,leilihh/libvirt,jfehlig/libvirt,VenkatDatta/libvirt,jeckersb/libvirt,rlaager/libvirt,danwent/libvirt-ovs,danwent/libvirt-ovs,foomango/libvirt,agx/libvirt,rlaager/libvirt,leilihh/libvirt,rlaager/libvirt,foomango/libvirt,libvirt/libvirt,elmarco/libvirt,fabianfreyer/libvirt,cbosdo/libvirt,foomango/libvirt,datto/libvirt,emaste/libvirt,eskultety/libvirt,shugaoye/libvirt,emaste/libvirt,warewolf/libvirt,elmarco/libvirt,taget/libvirt,libvirt/libvirt,soulxu/libvirt-xuhj,usc-isi/libvirt,rmarwaha/libvirt,siboulet/libvirt-openvz,andreabolognani/libvirt,wiedi/libvirt,agx/libvirt,datto/libvirt,jardasgit/libvirt,novel/fbsd-libvirt,eskultety/libvirt,olafhering/libvirt,trainstack/libvirt,cbosdo/libvirt,rmarwaha/libvirt,usc-isi/libvirt,dumbbell/libvirt,jfehlig/libvirt,kantai/libvirt-vfork,bjzhang/libvirt,bjzhang/libvirt,bjzhang/libvirt,rlaager/libvirt,zippy2/libvirt,jardasgit/libvirt,danwent/libvirt-ovs,agx/libvirt,eskultety/libvirt,crobinso/libvirt,novel/fbsd-libvirt,rmarwaha/libvirt1,shugaoye/libvirt,trainstack/libvirt,VenkatDatta/libvirt,andreabolognani/libvirt,libvirt/libvirt,warewolf/libvirt,rmarwaha/libvirt1,emaste/libvirt,kantai/libvirt-vfork,elmarco/libvirt,cbosdo/libvirt,iam-TJ/libvirt,taget/libvirt,andreabolognani/libvirt,crobinso/libvirt,novel/fbsd-libvirt,warewolf/libvirt,zippy2/libvirt,trainstack/libvirt,warewolf/libvirt,jeckersb/libvirt,novel/fbsd-libvirt,taget/libvirt,leilihh/libvirt,rmarwaha/libvirt,rmarwaha/libvirt,rlaager/libvirt,crobinso/libvirt,dumbbell/libvirt,wiedi/libvirt,olafhering/libvirt,jfehlig/libvirt,nertpinx/libvirt,shugaoye/libvirt,nertpinx/libvirt,danwent/libvirt-ovs,dumbbell/libvirt