[VOL-5584] Replace deprecated [Return] settings with RETURN across repository

Change-Id: Ia0231ed837c4407440fe93c6bf36c7a55edb7bea
Signed-off-by: Serkant Uluderya <serkant.uluderya@netsia.com>
diff --git a/tests/software-upgrades/ONU_Upgrade.robot b/tests/software-upgrades/ONU_Upgrade.robot
index beaedf8..ba56e1e 100755
--- a/tests/software-upgrades/ONU_Upgrade.robot
+++ b/tests/software-upgrades/ONU_Upgrade.robot
@@ -822,7 +822,7 @@
     ${timeCurrent} =    Get Current Date
     ${timeTotalMs} =    Subtract Date From Date    ${timeCurrent}    ${timeStart}    result_format=number
     Remove Adapter Image    ${image_version}    ${onu_device_id}
-    [Return]    ${timeTotalMs}
+    RETURN    ${timeTotalMs}
 
 Do ONU Upgrade Image Download Simultaneously
     [Documentation]    This keyword performs the ONU Upgrade Image Download Simultaneously on all ONUs test