refact: Small part of the grammar optimization

src/thunk.ts

@@ -55,7 +55,7 @@ export const thunk = function thunk(sel: string, key?: any, fn?: any, args?: any
   }
   return h(sel, {
     key: key,
-    hook: {init: init, prepatch: prepatch},
+    hook: {init, prepatch},
     fn: fn,
     args: args
   });

src/vnode.ts

@@ -42,8 +42,7 @@ export function vnode(sel: string | undefined,
                       text: string | undefined,
                       elm: Element | Text | undefined): VNode {
   let key = data === undefined ? undefined : data.key;
-  return {sel: sel, data: data, children: children,
-          text: text, elm: elm, key: key};
+  return {sel, data, children, text, elm, key};
 }
 
 export default vnode;