Documentation: smb: smbdirect: Convert KSMBD docs link

Convert KSMBD docs link to internal link.

Signed-off-by: Bagas Sanjaya <[email protected]>

Author: bagasme

Documentation/filesystems/smb/smbdirect.rst

@@ -76,8 +76,8 @@ Installation
 Setup and Usage
 ================
 
-- Set up and start a KSMBD server as described in the `KSMBD documentation
-  <https://www.kernel.org/doc/Documentation/filesystems/smb/ksmbd.rst>`_.
+- Set up and start a KSMBD server as described in the :doc:`KSMBD documentation
+  <ksmbd>`.
   Also add the "server multi channel support = yes" parameter to ksmbd.conf.
 
 - On the client, mount the share with `rdma` mount option to use SMB Direct