qemu: detect arch correctly for KVM
qemu: detect arch correctly for KVM

When running under KVM, the arch is usually set to i686 because
the name of the emulator is not qemu-system-x86_64.  Use the host
arch instead.

Signed-off-by: Paolo Bonzini <69d3ebcf5ee4e7f05a50dc23cd96655b730804b4@redhat.com>

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