[admin-guide] Fix the incorrect command

BTW, Use the OpenStack CLI instead of nova.

Change-Id: I2b5299c0fe315db5e92b5b604a50ade4efd05f03
Closes-Bug: #1595770

doc/admin-guide/source/cli_nova_specify_host.rst

@@ -7,14 +7,16 @@ host instances are launched on and which roles can boot instances
 on this host.
 
 #. To select the host where instances are launched, use
-   the :option:`--availability_zone ZONE:HOST` parameter on the
-   :command:`nova boot` command.
+   the :option:`--availability-zone ZONE:HOST` parameter on the
+   :command:`openstack server create` command.
 
    For example:
 
    .. code-block:: console
 
-      $ nova boot --image <uuid> --flavor m1.tiny --key_name test --availability-zone nova:server2
+      $ openstack server create --image IMAGE --flavor m1.tiny \
+        --key-name KEY --availability-zone ZONE:HOST \
+        --nic net-id=UUID SERVER
 
 #. To specify which roles can launch an instance on a
    specified host, enable the ``create:forced_host`` option in
@@ -22,15 +24,15 @@ on this host.
    enabled for only the admin role.
 
 #. To view the list of valid compute hosts, use the
-   :command:`nova hypervisor-list` command.
+   :command:`openstack hypervisor list` command.
 
    .. code-block:: console
 
-      $ nova hypervisor-list
+      $ openstack hypervisor list
       +----+---------------------+
-      | ID | Hypervisor hostname |
+      | ID | Hypervisor Hostname |
       +----+---------------------+
-      | 1  | server2             |
-      | 2  | server3             |
-      | 3  | server4             |
+      |  1 | server2             |
+      |  2 | server3             |
+      |  3 | server4             |
       +----+---------------------+