waiting for the OLT to go down in OLT soft reboot tests

Change-Id: Ib03f614d1c55ef3150045c3839e1db7b8d4247d6
diff --git a/tests/functional/Voltha_FailureScenarios2.robot b/tests/functional/Voltha_FailureScenarios2.robot
index 289cca7..8047963 100644
--- a/tests/functional/Voltha_FailureScenarios2.robot
+++ b/tests/functional/Voltha_FailureScenarios2.robot
@@ -69,6 +69,9 @@
     Wait Until Keyword Succeeds    ${timeout}    2s    Perform Sanity Test
     # Reboot the OLT using "voltctl device reboot" command
     Reboot Device    ${olt_device_id}
+    # Wait for the OLT to actually go down
+    Wait Until Keyword Succeeds    360s    5s    Validate OLT Device    ENABLED    UNKNOWN    UNREACHABLE
+    ...    ${olt_serial_number}
     #Verify that ping fails
     FOR    ${I}    IN RANGE    0    ${num_onus}
         ${src}=    Set Variable    ${hosts.src[${I}]}
@@ -78,7 +81,6 @@
         ...    Check Ping    False    ${dst['dp_iface_ip_qinq']}    ${src['dp_iface_name']}
         ...    ${src['ip']}    ${src['user']}    ${src['pass']}    ${src['container_type']}    ${src['container_name']}
     END
-    # Wait for the OLT to come back up
     Run Keyword If    ${has_dataplane}    Wait Until Keyword Succeeds    120s    10s
     ...    Check Remote System Reachability    True    ${olt_ssh_ip}
     # Waiting extra time for the ONUs to come up