audit small applets and mark some of them as NOFORK.

Put big scary warnings in relevant places.

coreutils/dirname.c

@@ -10,10 +10,10 @@
 /* BB_AUDIT SUSv3 compliant */
 /* http://www.opengroup.org/onlinepubs/007904975/utilities/dirname.html */
 
-#include <stdio.h>
-#include <stdlib.h>
 #include "busybox.h"
 
+/* This is a NOFORK applet. Be very careful! */
+
 int dirname_main(int argc, char **argv);
 int dirname_main(int argc, char **argv)
 {
@@ -23,5 +23,5 @@ int dirname_main(int argc, char **argv)
 
 	puts(dirname(argv[1]));
 
-	fflush_stdout_and_exit(EXIT_SUCCESS);
+	return fflush(stdout);
 }