fix callback function

services/database/share.js

@@ -56,7 +56,7 @@ exports.exists = function (object_id, callback) {
   dbo.collection("shares")
     .findOne({ object_id: ObjectId(object_id) })
     .then(result => {
-      cp(callback, result);
+      cb(callback, result);
     });
 }
 
@@ -75,7 +75,7 @@ exports.add = function (item, callback) {
           ])
           .toArray((err, result) => {
             if (err) throw err;
-            cp(callback, result[0]);
+            cb(callback, result[0]);
           })
       }
     });