Fix copyright header of position_with_affinity.h

This patch removes a leftover "/*" from the copyright header of the file.

Notry: True
Change-Id: I2d44da15a07e9003756647dfc631a8e813259380
Reviewed-on: https://chromium-review.googlesource.com/1025180Reviewed-by: Yoshifumi Inoue <yosin@chromium.org>
Commit-Queue: Yoshifumi Inoue <yosin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#552959}

third_party/blink/renderer/core/editing/position_with_affinity.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file./*
+// found in the LICENSE file.
 
 #ifndef THIRD_PARTY_BLINK_RENDERER_CORE_EDITING_POSITION_WITH_AFFINITY_H_
 #define THIRD_PARTY_BLINK_RENDERER_CORE_EDITING_POSITION_WITH_AFFINITY_H_