qemu: report more proper error for unsupported graphics
qemu: report more proper error for unsupported graphics

Report VIR_ERR_CONFIG_UNSUPPORTED instead of VIR_ERR_INTERNAL_ERROR,
as it's valid in our domain schema, just unsupported by hypervisor
here.

* src/qemu/qemu_command.c

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