Disable %n in printf and vfwprintf.

Bug: 14492135
Change-Id: If190bede29e5f68a65043ddbe8e878c660933d03
diff --git a/libc/stdio/local.h b/libc/stdio/local.h
index 5fb2292..907fd21 100644
--- a/libc/stdio/local.h
+++ b/libc/stdio/local.h
@@ -102,6 +102,7 @@
 #define FLOATING_POINT
 #define PRINTF_WIDE_CHAR
 #define SCANF_WIDE_CHAR
+#define NO_PRINTF_PERCENT_N
 
 /* OpenBSD exposes these in <stdio.h>, but we only want them exposed to the implementation. */
 __BEGIN_DECLS