Add minor fix to a bug in BMC cleanup module

Currently bmc_cleanup test fails if the cleanup directory doesn't exist
in the target BMC machine. This in turn is failing standby_bmc test
and AES health checks.

Change-Id: Ic65aed3724857e4eb3561476ddb0c729dfa0689b
Signed-off-by: Sunil M <sunilmam@us.ibm.com>
diff --git a/extended/standby_bmc.robot b/extended/standby_bmc.robot
index c30d6ed..9c0c9eb 100644
--- a/extended/standby_bmc.robot
+++ b/extended/standby_bmc.robot
@@ -56,8 +56,9 @@
 
     Run Keyword If  '${MAC_ADDRESS}' != '${EMPTY}'
     ...  Check And Reset MAC
-
-    Run Keyword If  '${CLEANUP_DIR_PATH}' != '${EMPTY}'
+    ${rc}=  Execute Command  find ${CLEANUP_DIR_PATH}
+    ...  return_stdout=False  return_rc=True
+    Run Keyword If  '${CLEANUP_DIR_PATH}' != '${EMPTY}' and ${rc} == 0
     ...  Cleanup Dir