Update c++-cn.html.markdown

Line 325: update myDog.printDog() to myDog.print().

zh-cn/c++-cn.html.markdown

@@ -322,7 +322,7 @@ int main() {
     Dog myDog; // 此时显示“A dog has been constructed”
     myDog.setName("Barkley");
     myDog.setWeight(10);
-    myDog.printDog(); // 显示“Dog is Barkley and weighs 10 kg”
+    myDog.print(); // 显示“Dog is Barkley and weighs 10 kg”
     return 0;
 } // 显示“Goodbye Barkley”