spec: fix typo in the numa hook summary

Change-Id: I03eee4df9db645af51e75661f382b123b2df6919
Signed-off-by: Federico Simoncelli <fsimonce@redhat.com>
Reviewed-on: http://gerrit.ovirt.org/10436
Reviewed-by: Maor Lipchuk <mlipchuk@redhat.com>