fix waitForData + data hook promise sugar

Author: yyx990803

src/pipeline.js

@@ -274,12 +274,13 @@ function loadData (component, transition, hook, cb, cleanup) {
     })
     if (!promises.length) {
       component.$loadingRouteData = false
+      cb && cb()
     } else {
       promises[0].constructor.all(promises).then(_ => {
         component.$loadingRouteData = false
+        cb && cb()
       }, onError)
     }
-    cb && cb(data)
   }, {
     cleanup: cleanup,
     expectData: true