virDomainNetDefParseXML: avoid leak upon multiple "filterref"
virDomainNetDefParseXML: avoid leak upon multiple "filterref"

* src/conf/domain_conf.c (virDomainNetDefParseXML): Don't leak
memory when parsing two or more "filterref" elements.

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