qemu: Report error on failure to set isolation group
qemu: Report error on failure to set isolation group

This is more user-friendly because the error will be
displayed directly instead of being buried in the log.

Signed-off-by: Andrea Bolognani <3ada0bee826c753786fdbba72243dfba997094cf@redhat.com>
Reviewed-by: Pavel Hrdina <d4772d05997b8abf035041e3b4f4996380ea7e7a@redhat.com>

jfehlig/libvirt,eskultety/libvirt,fabianfreyer/libvirt,jardasgit/libvirt,zippy2/libvirt,andreabolognani/libvirt,fabianfreyer/libvirt,libvirt/libvirt,jardasgit/libvirt,olafhering/libvirt,nertpinx/libvirt,eskultety/libvirt,zippy2/libvirt,zippy2/libvirt,jardasgit/libvirt,crobinso/libvirt,eskultety/libvirt,olafhering/libvirt,zippy2/libvirt,libvirt/libvirt,jfehlig/libvirt,nertpinx/libvirt,jfehlig/libvirt,andreabolognani/libvirt,crobinso/libvirt,fabianfreyer/libvirt,libvirt/libvirt,andreabolognani/libvirt,andreabolognani/libvirt,jardasgit/libvirt,crobinso/libvirt,eskultety/libvirt,eskultety/libvirt,libvirt/libvirt,jardasgit/libvirt,nertpinx/libvirt,olafhering/libvirt,nertpinx/libvirt,jfehlig/libvirt,olafhering/libvirt,andreabolognani/libvirt,crobinso/libvirt,nertpinx/libvirt,fabianfreyer/libvirt,fabianfreyer/libvirt