fix validate device

Change-Id: I9d63ba12b14e6bdd70931910f4fdbcdffb6adc97
diff --git a/tests/functional/Voltha_ErrorScenarios.robot b/tests/functional/Voltha_ErrorScenarios.robot
index 4bc83dc..aabeb0d 100644
--- a/tests/functional/Voltha_ErrorScenarios.robot
+++ b/tests/functional/Voltha_ErrorScenarios.robot
@@ -72,7 +72,7 @@
     Set Suite Variable    ${olt_device_id}
     ${timeout}    Set Variable    180s
     Wait Until Keyword Succeeds    ${timeout}    5s    Validate OLT Device    PREPROVISIONED    UNKNOWN    UNKNOWN
-    ...    ${EMPTY}    ${olt_device_id}
+    ...    ${olt_device_id}
     ${rc}    ${output}=    Run and Return Rc and Output
     ...    ${VOLTCTL_CONFIG}; voltctl device create -t openolt -H ${olt_ip}:${OLT_PORT}
     Should Not Be Equal As Integers    ${rc}    0
@@ -179,7 +179,7 @@
     Set Suite Variable    ${olt_device_id}
     #validate olt states
     Wait Until Keyword Succeeds    ${timeout}    5s    Validate OLT Device    PREPROVISIONED    UNKNOWN    UNKNOWN
-    ...    ${EMPTY}    ${olt_device_id}
+    ...    ${olt_device_id}
     #Try disabling pre-provisioned OLT
     ${rc}    ${output}=    Run and Return Rc and Output    ${VOLTCTL_CONFIG}; voltctl device disable ${olt_device_id}
     Should Be Equal As Integers    ${rc}    0
@@ -216,7 +216,7 @@
     Set Suite Variable    ${olt_device_id}
     #validate olt states
     Wait Until Keyword Succeeds    ${timeout}    5s    Validate OLT Device    PREPROVISIONED    UNKNOWN    UNKNOWN
-    ...    ${EMPTY}    ${olt_device_id}
+    ...    ${olt_device_id}
     #Enable the created OLT device
     Enable Device    ${olt_device_id}
     Wait Until Keyword Succeeds    ${timeout}    5s    Validate OLT Device    ENABLED    ACTIVE    REACHABLE
@@ -256,7 +256,7 @@
     ${olt_device_id}=    Create Device    ${olt_ip}    ${OLT_PORT}
     Set Suite Variable    ${olt_device_id}
     Wait Until Keyword Succeeds    ${timeout}    5s    Validate OLT Device    PREPROVISIONED    UNKNOWN    UNKNOWN
-    ...    ${EMPTY}    ${olt_device_id}
+    ...    ${olt_device_id}
     Enable Device    ${olt_device_id}
     Wait Until Keyword Succeeds    ${timeout}    5s    Validate OLT Device    ENABLED    ACTIVE    REACHABLE
     ...    ${olt_serial_number}