Documentation: fix admin-guide doc refs

Make admin-guide document refs valid.

Signed-off-by: Tom Saeger <tom.saeger@oracle.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index a342739..957b931 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -3134,7 +3134,7 @@
 
 	plip=		[PPT,NET] Parallel port network link
 			Format: { parport<nr> | timid | 0 }
-			See also Documentation/parport.txt.
+			See also Documentation/admin-guide/parport.rst.
 
 	pmtmr=		[X86] Manual setup of pmtmr I/O Port.
 			Override pmtimer IOPort with a hex value.