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

Change-Id: Iba95a07bb1ed6230b9a900448bf294355a58285c
diff --git a/config-models/aether-3.x/files/yang/upf.yang b/config-models/aether-3.x/files/yang/upf.yang
index 1c92214..3c56722 100755
--- a/config-models/aether-3.x/files/yang/upf.yang
+++ b/config-models/aether-3.x/files/yang/upf.yang
@@ -24,6 +24,7 @@
         type yg:yang-identifier {
             length 1..32;
         }
+    description "The typedef for upf-id";
   }
 
   container upf {
@@ -75,7 +76,7 @@
         mandatory true;
         description
           "Link to enterprise that owns this Access Point List";
-      }      
+      }
     }
-  } 
+  }
 }