Update Redfish-Reference-Checker and Redfish-Service-Validator suites

Changes:
    - lib/dmtf_tools_utils.robot to return the RC
    - Update test code to handle rc returnning

Resolves  openbmc/openbmc-test-automation#2178
Resolves  openbmc/openbmc-test-automation#2179

Change-Id: Ia9c6f3ea10ed2a25c31cf9c8af84680a441fc954
Signed-off-by: George Keishing <gkeishin@in.ibm.com>
diff --git a/lib/dmtf_tools_utils.robot b/lib/dmtf_tools_utils.robot
index 1fb538f..9387c51 100644
--- a/lib/dmtf_tools_utils.robot
+++ b/lib/dmtf_tools_utils.robot
@@ -36,7 +36,7 @@
 
     ${rc}  ${output}=  Shell Cmd  ${command_string}  ignore_err=${check_error}
     Log  ${output}
-    [Return]  ${output}
+    [Return]  ${rc}  ${output}
 
 
 Redfish Service Validator Result