Documentation: update stable tree link

The link to stable tree is redirected to
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git. Update
accordingly.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Sasha Levin <sashal@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: stable@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com>
Link: https://lore.kernel.org/r/20220314113329.485372-6-bagasdotme@gmail.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Documentation/process/stable-kernel-rules.rst

@@ -170,7 +170,7 @@ Trees
  - The finalized and tagged releases of all stable kernels can be found
    in separate branches per version at:
 
-	https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git
+	https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
 
  - The release candidate of all stable kernel versions can be found at: