Redfish service validator error checking

Changes:
    -  Added messsage checking from output due to redfish
       retry error when server failed to respond

Tested:
    - Ran test with error and without to ensure it catches
      the failure.

Change-Id: I5a29e0f40dc4fa4d0448bd63d2c54d0dc453f676
Signed-off-by: George Keishing <gkeishin@in.ibm.com>
diff --git a/lib/dmtf_tools_utils.robot b/lib/dmtf_tools_utils.robot
index 9387c51..6f370a0 100644
--- a/lib/dmtf_tools_utils.robot
+++ b/lib/dmtf_tools_utils.robot
@@ -45,7 +45,9 @@
 
     # Example:
     # Validation has failed: 9 problems found
-    Should Not Contain  ${tool_output}  Validation has failed
+    # Service could not be started: RetriesExhaustedError()
+    Should Not Contain Any  ${tool_output}  Validation has failed
+    ...  Service could not be started: RetriesExhaustedError()
 
 
 Redfish JsonSchema ResponseValidator Result