check_swap - fix comment

Signed-off-by: Davide Madrisan <davide.madrisan@gmail.com>

plugins/check_swap.c

@@ -1,6 +1,6 @@
 /*****************************************************************************
 * 
-* Nagios check_disk plugin
+* Nagios check_swap plugin
 * 
 * License: GPL
 * Copyright (c) 2000 Karl DeBisschop (kdebisschop@users.sourceforge.net)