added-yang-linter-and-resolved-all-error-produced-by it

Change-Id: Iba95a07bb1ed6230b9a900448bf294355a58285c
diff --git a/config-models/aether-4.x/files/yang/onf-upf.yang b/config-models/aether-4.x/files/yang/onf-upf.yang
index a8a7c4c..5c8be50 100755
--- a/config-models/aether-4.x/files/yang/onf-upf.yang
+++ b/config-models/aether-4.x/files/yang/onf-upf.yang
@@ -25,6 +25,7 @@
         type yg:yang-identifier {
             length 1..32;
         }
+   description "The typedef for upf-id";
   }
 
   container upf {
@@ -57,7 +58,7 @@
       leaf config-endpoint {
         type inet:uri;
         description "url for configuring the UPF";
-      }         
+      }
 
       leaf display-name {
         type string {