set of_id suite variable in sanity tests

Change-Id: Iccc85ffa8e6b828c045d7d5e3615d28f4e4ad06d
diff --git a/tests/sanity/sanity.robot b/tests/sanity/sanity.robot
index e6e76d1..bbbadc1 100644
--- a/tests/sanity/sanity.robot
+++ b/tests/sanity/sanity.robot
@@ -53,6 +53,7 @@
     [Documentation]    Verifies the BBSIM-OLT device is activated in onos
     [Tags]    sanity
     ${of_id}=    Wait Until Keyword Succeeds    ${timeout}    5s    Validate OLT Device in ONOS    ${BBSIM_OLT_SN}
+    Set Suite Variable    ${of_id}
 
 Check EAPOL Flows in ONOS
     [Documentation]    Validates eapol flows for the onu are pushed from voltha