as man page states, lower case undoes upper case. add support for little s,

no security, for consistency.  use of this option is discouraged. :)
ok deraadt guenther millert

src/lib/libc/stdlib/malloc.c

@@ -1,4 +1,4 @@
-/*	$OpenBSD: malloc.c,v 1.137 2011/05/20 20:02:08 otto Exp $	*/
+/*	$OpenBSD: malloc.c,v 1.138 2011/06/20 18:04:06 tedu Exp $	*/
 /*
  * Copyright (c) 2008 Otto Moerbeek <otto@drijf.net>
  *
@@ -548,6 +548,10 @@ omalloc_init(struct dir_info **dp)
 			case 'R':
 				mopts.malloc_realloc = 1;
 				break;
+			case 's':
+				mopts.malloc_freeprot = mopts.malloc_junk = 0;
+				mopts.malloc_guard = 0;
+				break;
 			case 'S':
 				mopts.malloc_freeprot = mopts.malloc_junk = 1;
 				mopts.malloc_guard = MALLOC_PAGESIZE;