Ignore expired session while deleting

This is to prevent causing failure while running longer test bucket
where a session could have been just expired.

Change-Id: If712b87a5a6af550d1e3502643e63b67f25362b3
Signed-off-by: George Keishing <gkeishin@in.ibm.com>
diff --git a/openpower/ext_interfaces/test_lock_management.robot b/openpower/ext_interfaces/test_lock_management.robot
index 7aa9c69..0addaa6 100644
--- a/openpower/ext_interfaces/test_lock_management.robot
+++ b/openpower/ext_interfaces/test_lock_management.robot
@@ -580,7 +580,7 @@
     # new_sess_req     Create a new session before acquiring a lock if True.
 
     # Delete the session.
-    Run Keyword If  ${new_sess_req} == ${True}  Delete All Redfish Sessions
+    Run Keyword If  ${new_sess_req} == ${True}  Run Keyword And Ignore Error  Delete All Redfish Sessions
 
     # Get REST session to BMC.
     Run Keyword If  ${new_sess_req} == ${True}  Create New Session
@@ -622,7 +622,7 @@
     [Documentation]  Test teardown execution.
 
     FFDC On Test Case Fail
-    Delete All Redfish Sessions
+    Run Keyword And Ignore Error  Delete All Redfish Sessions
 
 
 Return Session Id And Session Key