Minor change in rest_lib to simplify code

Change-Id: Ica69341d3bca4dd5bc1f85d3b73f46da191c6529
Signed-off-by: garciadeblas <gerardo.garciadeblas@telefonica.com>
diff --git a/robot-systest/lib/rest_lib.resource b/robot-systest/lib/rest_lib.resource
index 6bec42d..654290d 100644
--- a/robot-systest/lib/rest_lib.resource
+++ b/robot-systest/lib/rest_lib.resource
@@ -66,8 +66,7 @@
 Get Resource Directory
     [Documentation]   Return Directory corresponding to the resources folder
     ${Directory}=   Replace String   ${CURDIR}   lib   resources
-    ${json_path}=   Set Variable   ${Directory}
-    RETURN   ${json_path}
+    RETURN   ${Directory}
 
 Post Api Request
     [Documentation]   Send to OSM a POST API message to OSM to the given uri with the given json data,