[VOL-4237] Keep log files unless  is set to false

Change-Id: I2d11554b49c12d13c354f0c5f883962e4d8f10bc
diff --git a/tests/functional/Voltha_FailureScenarios.robot b/tests/functional/Voltha_FailureScenarios.robot
index e7a91ad..d7e35ae 100755
--- a/tests/functional/Voltha_FailureScenarios.robot
+++ b/tests/functional/Voltha_FailureScenarios.robot
@@ -57,6 +57,10 @@
 # Per-test logging on failure is turned off by default; set this variable to enable
 ${container_log_dir}    ${None}
 
+# logging flag to enable Collect Logs, can be passed via the command line too
+# example: -v logging:False
+${logging}    True
+
 *** Test Cases ***
 Verify ONU after rebooting physically
     [Documentation]    Test the ONU functionality by physically turning on/off ONU.