qemu: substitute missing model name for host-passthrough
qemu: substitute missing model name for host-passthrough

Before:
  $ uname -m
  s390x
  $ cat passthrough-cpu.xml
  <cpu check="none" mode="host-passthrough" />
  $ virsh hypervisor-cpu-compare passthrough-cpu.xml
  error: Failed to compare hypervisor CPU with passthrough-cpu.xml
  error: internal error: unable to execute QEMU command 'query-cpu-model-comp
  arison': Invalid parameter type for 'modelb.name', expected: string

After:
  $ virsh hypervisor-cpu-compare passthrough-cpu.xml
  CPU described in passthrough-cpu.xml is identical to the CPU provided by hy
  pervisor on the host

Signed-off-by: Tim Wiederhake <da93ee425e056cfcf1ddac9fc87851b25464abf4@redhat.com>
Signed-off-by: Collin Walling <6a8456d624ba23d3de7a39e51739b800eab4ccb7@linux.ibm.com>
Reviewed-by: Jiri Denemark <62bdf77dc47919a4d59a91822129d14633cfca81@redhat.com>

zippy2/libvirt,libvirt/libvirt,jardasgit/libvirt,nertpinx/libvirt,nertpinx/libvirt,zippy2/libvirt,olafhering/libvirt,crobinso/libvirt,jardasgit/libvirt,libvirt/libvirt,olafhering/libvirt,olafhering/libvirt,libvirt/libvirt,zippy2/libvirt,jfehlig/libvirt,libvirt/libvirt,jardasgit/libvirt,nertpinx/libvirt,zippy2/libvirt,olafhering/libvirt,jfehlig/libvirt,crobinso/libvirt,crobinso/libvirt,jardasgit/libvirt,jfehlig/libvirt,nertpinx/libvirt,crobinso/libvirt,jardasgit/libvirt,nertpinx/libvirt,jfehlig/libvirt