don't use initializer property for decorators on concise methods in object literals

src/babel/transformation/transformers/es7/decorators.js

@@ -26,7 +26,7 @@ export function ObjectExpression(node, parent, scope, file) {
     if (prop.decorators) memoiseDecorators(prop.decorators, scope);
 
 
-    if (prop.kind === "init") {
+    if (prop.kind === "init" && !prop.method) {
       prop.kind = "";
       prop.value = t.functionExpression(null, [], t.blockStatement([
         t.returnStatement(prop.value)

test/core/fixtures/transformation/es7.decorators/object/expected.js

@@ -3,9 +3,7 @@
 var obj = babelHelpers.createDecoratedObject([{
   key: "bar",
   decorators: [foo],
-  initializer: function () {
-    return function bar() {};
-  }
+  value: function bar() {}
 }, {
   key: "foo",
   decorators: [bar],