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/process/adding-syscalls.rst b/Documentation/process/adding-syscalls.rst
index f5b5b1a..8cc25a0 100644
--- a/Documentation/process/adding-syscalls.rst
+++ b/Documentation/process/adding-syscalls.rst
@@ -3,7 +3,7 @@
 
 This document describes what's involved in adding a new system call to the
 Linux kernel, over and above the normal submission advice in
-:ref:`Documentation/SubmittingPatches <submittingpatches>`.
+:ref:`Documentation/process/submitting-patches.rst <submittingpatches>`.
 
 
 System Call Alternatives