[network] Check ovs port existence in straight way

Change-Id: I9d08c0756bed19e15651b2bf59e2f5c198213b34
Closes-Bug: PROD-27987
diff --git a/linux/network/interface.sls b/linux/network/interface.sls
index 771bd5e..2cfdb3b 100644
--- a/linux/network/interface.sls
+++ b/linux/network/interface.sls
@@ -104,8 +104,8 @@
 
 add_int_{{ int_name }}_to_ovs_bridge_{{ interface_name }}:
   cmd.run:
-    - unless: ovs-vsctl show | grep {{ int_name }}
     - name: ovs-vsctl{%- if network.ovs_nowait %} --no-wait{%- endif %} add-port {{ interface_name }} {{ int_name }}
+    - unless: ovs-vsctl list-ports {{ interface_name }} | grep -qFx {{ int_name }}
 {%- endif %}
 
 {%- endfor %}