Documentation: translations: update linux cross reference link

The old link to source code cross reference does not work now. Though
the link has updated by commit 1d12554f0abbc7d17dce8d1b7b25f4e27555e6d7
("Documentation: HOWTO: update code cross reference link"), there are
few obsolete links yet. This commit update them.

Signed-off-by: SeongJae Park <sj38.park@gmail.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
diff --git a/Documentation/ja_JP/HOWTO b/Documentation/ja_JP/HOWTO
index 28109a8..8d5465d 100644
--- a/Documentation/ja_JP/HOWTO
+++ b/Documentation/ja_JP/HOWTO
@@ -245,7 +245,7 @@
 自己参照方式で、索引がついた web 形式で、ソースコードを参照することが
 できます。この最新の素晴しいカーネルコードのリポジトリは以下で見つかり
 ます-
-	http://lxr.linux.no/+trees
+	http://lxr.free-electrons.com/
 
 開発プロセス
 -----------------------