docs: fix locations of several documents that got moved

The previous patch renamed several files that are cross-referenced
along the Kernel documentation. Adjust the links to point to
the right places.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
diff --git a/Documentation/filesystems/locks.txt b/Documentation/filesystems/locks.txt
index 2cf8108..5368690 100644
--- a/Documentation/filesystems/locks.txt
+++ b/Documentation/filesystems/locks.txt
@@ -19,7 +19,7 @@
 
 This should not cause problems for anybody, since everybody using a
 2.1.x kernel should have updated their C library to a suitable version
-anyway (see the file "Documentation/Changes".)
+anyway (see the file "Documentation/process/changes.rst".)
 
 1.2 Allow Mixed Locks Again
 ---------------------------