use NULL as last argument to execl, not 0

git-svn-id: svn://svn.h5l.se/heimdal/trunk/heimdal@14747 ec53bebd-3082-4978-b11e-865c3cabbd6b

appl/dceutils/testpag.c

@@ -141,7 +141,7 @@ main(argc, argv)
         "FILE:/opt/dcelocal/var/security/creds/dcecred_%8.8x", 
         pag);
       esetenv("KRB5CCNAME",ccname,1);
-      execl("/bin/csh","csh",0);
+      execl("/bin/csh", "csh", NULL);
     }
     else {
       fprintf(stderr," Not a good pag value\n");