Our *int_fast{8,16}_t types are int/unsigned int, so SCN*FAST{8,16}

shouldn't include 'hh' or 'h'.
problem noted by Andreas Kusalananda Kähäri (andreas.kahari(at)abc.se)
ok deraadt@ martijn@

src/include/inttypes.h

@@ -1,4 +1,4 @@
-/*	$OpenBSD: inttypes.h,v 1.11 2013/06/11 15:59:16 matthew Exp $	*/
+/*	$OpenBSD: inttypes.h,v 1.12 2018/11/22 21:20:38 guenther Exp $	*/
 
 /*
  * Copyright (c) 1997, 2005 Todd C. Miller <Todd.Miller@courtesan.com>
@@ -162,8 +162,8 @@
 #define	SCNdLEAST32		"d"		/* int_least32_t */
 #define	SCNdLEAST64		"lld"		/* int_least64_t */
 
-#define	SCNdFAST8		"hhd"		/* int_fast8_t */
-#define	SCNdFAST16		"hd"		/* int_fast16_t */
+#define	SCNdFAST8		"d"		/* int_fast8_t */
+#define	SCNdFAST16		"d"		/* int_fast16_t */
 #define	SCNdFAST32		"d"		/* int_fast32_t */
 #define	SCNdFAST64		"lld"		/* int_fast64_t */
 
@@ -180,8 +180,8 @@
 #define	SCNiLEAST32		"i"		/* int_least32_t */
 #define	SCNiLEAST64		"lli"		/* int_least64_t */
 
-#define	SCNiFAST8		"hhi"		/* int_fast8_t */
-#define	SCNiFAST16		"hi"		/* int_fast16_t */
+#define	SCNiFAST8		"i"		/* int_fast8_t */
+#define	SCNiFAST16		"i"		/* int_fast16_t */
 #define	SCNiFAST32		"i"		/* int_fast32_t */
 #define	SCNiFAST64		"lli"		/* int_fast64_t */
 
@@ -199,8 +199,8 @@
 #define	SCNoLEAST32		"o"		/* uint_least32_t */
 #define	SCNoLEAST64		"llo"		/* uint_least64_t */
 
-#define	SCNoFAST8		"hho"		/* uint_fast8_t */
-#define	SCNoFAST16		"ho"		/* uint_fast16_t */
+#define	SCNoFAST8		"o"		/* uint_fast8_t */
+#define	SCNoFAST16		"o"		/* uint_fast16_t */
 #define	SCNoFAST32		"o"		/* uint_fast32_t */
 #define	SCNoFAST64		"llo"		/* uint_fast64_t */
 
@@ -217,8 +217,8 @@
 #define	SCNuLEAST32		"u"		/* uint_least32_t */
 #define	SCNuLEAST64		"llu"		/* uint_least64_t */
 
-#define	SCNuFAST8		"hhu"		/* uint_fast8_t */
-#define	SCNuFAST16		"hu"		/* uint_fast16_t */
+#define	SCNuFAST8		"u"		/* uint_fast8_t */
+#define	SCNuFAST16		"u"		/* uint_fast16_t */
 #define	SCNuFAST32		"u"		/* uint_fast32_t */
 #define	SCNuFAST64		"llu"		/* uint_fast64_t */
 
@@ -235,8 +235,8 @@
 #define	SCNxLEAST32		"x"		/* uint_least32_t */
 #define	SCNxLEAST64		"llx"		/* uint_least64_t */
 
-#define	SCNxFAST8		"hhx"		/* uint_fast8_t */
-#define	SCNxFAST16		"hx"		/* uint_fast16_t */
+#define	SCNxFAST8		"x"		/* uint_fast8_t */
+#define	SCNxFAST16		"x"		/* uint_fast16_t */
 #define	SCNxFAST32		"x"		/* uint_fast32_t */
 #define	SCNxFAST64		"llx"		/* uint_fast64_t */