Fix to work with Perl 5.6

tmcd/ron/watchdog

@@ -43,6 +43,11 @@ my $vndir   = "/var/testbed";
 my $pidfile = "/var/run/emulab-watchdog.pid";
 my $noboot  = 0;
 
+#
+# Forward declarations for prototype checking
+#
+sub bootvnodes();
+
 #
 # Parse command arguments. Once we return from getopts, all that should be
 # left are the required arguments.