qemu: remove dead assignment
qemu: remove dead assignment

Detected by clang.

* src/qemu/qemu_migration.c (qemuMigrationToFile): Nothing later
uses is_reg.

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