fix(Kotlin): Remove empty lines (#1264)

codes/kotlin/utils/ListNode.kt

@@ -22,4 +22,4 @@ class ListNode(var _val: Int) {
             return dum.next
         }
     }
-}
+}

codes/kotlin/utils/PrintUtil.kt

@@ -104,4 +104,4 @@ fun printHeap(queue: Queue<Int>?) {
     println("堆的树状表示：")
     val root = TreeNode.listToTree(list)
     printTree(root)
-}
+}