libc: Remove sscanf() and timingsafe_bcmp()

sscanf() is unused and it doesn't work, so it doesn't make sense to
keep it.

timingsafe_bcmp() isn't used anywhere.

Change-Id: Ib5d28ff21d0f3ccc36c5c0fb5474b3384105cf80
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

lib/libc/libc.mk

 #
-# Copyright (c) 2016-2017, ARM Limited and Contributors. All rights reserved.
+# Copyright (c) 2016-2018, ARM Limited and Contributors. All rights reserved.
 #
 # SPDX-License-Identifier: BSD-3-Clause
 #
@@ -12,14 +12,12 @@ LIBC_SRCS	:=	$(addprefix lib/libc/,	\
 			printf.c			\
 			putchar.c			\
 			puts.c				\
-			sscanf.c			\
 			strchr.c			\
 			strcmp.c			\
 			strlen.c			\
 			strncmp.c			\
 			strnlen.c			\
-			subr_prf.c			\
-			timingsafe_bcmp.c)
+			subr_prf.c)
 
 INCLUDES	+=	-Iinclude/lib/libc		\
 			-Iinclude/lib/libc/sys

lib/libc/sscanf.c

-/*
- * Copyright (c) 2015-2018, ARM Limited and Contributors. All rights reserved.
- *
- * SPDX-License-Identifier: BSD-3-Clause
- */
-
-#include <stdio.h>
-#include <sys/cdefs.h>
-
-/*
- * TODO: This is not a real implementation of the sscanf() function. It just
- * returns the number of expected arguments based on the number of '%' found
- * in the format string.
- */
-int
-sscanf(const char *__restrict str, char const *__restrict fmt, ...)
-{
-	int ret = 0;
-
-	while (*fmt != '\0') {
-		if (*fmt++ == '%') {
-			ret++;
-		}
-	}
-
-	return ret;
-}

lib/libc/timingsafe_bcmp.c

-/*	$OpenBSD: timingsafe_bcmp.c,v 1.3 2015/08/31 02:53:57 guenther Exp $	*/
-/*
- * Copyright (c) 2010 Damien Miller.  All rights reserved.
- *
- * Permission to use, copy, modify, and distribute this software for any
- * purpose with or without fee is hereby granted, provided that the above
- * copyright notice and this permission notice appear in all copies.
- *
- * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
- * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
- * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
- * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
- * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
- * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
- * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
- */
-
-#include <sys/cdefs.h>
-__FBSDID("$FreeBSD$");
-
-#include <string.h>
-
-int __timingsafe_bcmp(const void *, const void *, size_t);
-
-int
-__timingsafe_bcmp(const void *b1, const void *b2, size_t n)
-{
-	const unsigned char *p1 = b1, *p2 = b2;
-	int ret = 0;
-
-	for (; n > 0; n--)
-		ret |= *p1++ ^ *p2++;
-	return (ret != 0);
-}
-
-__weak_reference(__timingsafe_bcmp, timingsafe_bcmp);