use single ssh connection to onos
It belongs to VOL-4041 and is the second part.
Keyword 'Execute ONOS CLI Command on open connection' is deprecated
and is replaced by keyword
'Execute ONOS CLI Command use single connection' for all test suites
and libraries.

Change-Id: Ib5078b50d22e812e927e437a0e6f0e249f95ee9a
diff --git a/tests/openonu-go-adapter/Voltha_ONUNegativeStateTests.robot b/tests/openonu-go-adapter/Voltha_ONUNegativeStateTests.robot
index 9dc9793..1a2ebf7 100755
--- a/tests/openonu-go-adapter/Voltha_ONUNegativeStateTests.robot
+++ b/tests/openonu-go-adapter/Voltha_ONUNegativeStateTests.robot
@@ -104,8 +104,6 @@
     ...    ELSE IF    "${techprofile}"=="1T4GEM"    Set Tech Profile    1T4GEM
     ...    ELSE IF    "${techprofile}"=="1T8GEM"    Set Tech Profile    1T8GEM
     ...    ELSE    Fail    The TechProfile (${techprofile}) is not valid!
-    ${onos_ssh_connection}    Open ONOS SSH Connection    ${ONOS_SSH_IP}    ${ONOS_SSH_PORT}
-    Set Suite Variable  ${onos_ssh_connection}
     # delete etcd MIB Template Data
     Delete MIB Template Data
     # delete etcd onu data
@@ -120,6 +118,6 @@
     Run Keyword If    ${pausebeforecleanup}    Log    Teardown will be continued...    console=yes
     Run Keyword If    ${teardown_device}    Delete All Devices and Verify
     Wait Until Keyword Succeeds    ${timeout}    1s    Validate Onu Data In Etcd    0    ${kvstoreprefix}    without_pm_data=False
-    Wait for Ports in ONOS for all OLTs      ${onos_ssh_connection}  0   BBSM    ${timeout}
+    Wait for Ports in ONOS for all OLTs      ${ONOS_SSH_IP}    ${ONOS_SSH_PORT}  0   BBSM    ${timeout}
     Close All ONOS SSH Connections
     Remove Tech Profile