Added fix for BMC dump test case

Fix:
   Power off code is added to prevent dump to offload to OS.

Change-Id: I7010adeffb6b98750cfb9dda5a9ea770e5c489d0
Signed-off-by: manashsarma <manashsarma@in.ibm.com>
diff --git a/redfish/managers/test_bmc_dumps.robot b/redfish/managers/test_bmc_dumps.robot
index 0129ef4..a684520 100644
--- a/redfish/managers/test_bmc_dumps.robot
+++ b/redfish/managers/test_bmc_dumps.robot
@@ -27,6 +27,7 @@
     [Documentation]  Delete non existing BMC dump and expect an error.
     [Tags]  Verify_Error_Response_For_Already_Deleted_Dump_Id
 
+    Redfish Power Off  stack_mode=skip
     ${dump_id}=  Create User Initiated BMC Dump Via Redfish
     Redfish Delete BMC Dump  ${dump_id}
     Run Keyword And Expect Error  ValueError: *  Redfish Delete BMC Dump  ${dump_id}