improve:add local variable declaration (vuejs#5462)

gebilaoxiong · yyx990803 · commit 3b4d16b0322d · 2017-04-18T11:42:38.000+08:00
diff --git a/src/core/vdom/patch.js b/src/core/vdom/patch.js
@@ -327,6 +327,7 @@ export function createPatchFunction (backend) {
 
   function removeAndInvokeRemoveHook (vnode, rm) {
     if (isDef(rm) || isDef(vnode.data)) {
+      let i
       const listeners = cbs.remove.length + 1
       if (isDef(rm)) {
         // we have a recursively passed down rm callback
