Update test case verification

Change-Id: I64d6db1d9984a48dd50d525bbacb97ab6f20e9c2
Signed-off-by: George Keishing <gkeishin@in.ibm.com>
diff --git a/redfish/service_root/test_service_root.robot b/redfish/service_root/test_service_root.robot
index 42c1edc..66a63a3 100644
--- a/redfish/service_root/test_service_root.robot
+++ b/redfish/service_root/test_service_root.robot
@@ -67,12 +67,17 @@
     # [{'@odata.id': '/redfish/v1/SessionService/Sessions/bOol3WlCI8'},
     #  {'@odata.id': '/redfish/v1/SessionService/Sessions/Yu3xFqjZr1'}]
     ${resp_list}=  redfish.List Request  SessionService/Sessions
-
     redfish.Delete  ${resp_list[1]}
 
     ${resp}=  redfish.List Request  SessionService/Sessions
     List Should Not Contain Value  ${resp}  ${resp_list[1]}
-    redfish.Logout
+
+    # BadRequestError: Invalid session resource:
+    # /redfish/v1/SessionService/Sessions/gAEabN5Q0t, return code: 401
+
+    ${error_message}=  Catenate  SEPARATOR=  BadRequestError: Invalid session resource:
+    ...  ${SPACE}${resp_list[1]}, return code: 401
+    Run Keyword And Expect Error  ${error_message}  redfish.Logout
 
 
 *** Keywords ***