cosmetics: trim trailing whitespace

When the license headers were updated, they accidentally contained
trailing whitespace, so unfortunately we have to touch all the files
again.

Change-Id: I236c05fade06589e417179c0444cb39b09e4200d
diff --git a/example_xma.c b/example_xma.c
index e5eca7a..69d14f4 100644
--- a/example_xma.c
+++ b/example_xma.c
@@ -1,10 +1,10 @@
 /*
  *  Copyright (c) 2010 The VP8 project authors. All Rights Reserved.
  *
- *  Use of this source code is governed by a BSD-style license 
+ *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
- *  in the file PATENTS.  All contributing project authors may 
+ *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */