memzero.[ch]: Define memzero() and strzero() as inline functions

There's no need to have these as macros, so use functions, which are a
lot safer: there's no need to worry about multiple evaluation of args,
and there's also more type safety.  Compiler warnings are also simpler,
as they don't dump all the nested macros.

Cc: Christian Göttsche <cgzones@googlemail.com>
Cc: Serge Hallyn <serge@hallyn.com>
Cc: Iker Pedrosa <ipedrosa@redhat.com>
Signed-off-by: Alejandro Colomar <alx@kernel.org>

lib/memzero.c

@@ -0,0 +1,17 @@
+/*
+ * SPDX-FileCopyrightText: 2023, Alejandro Colomar <alx@kernel.org>
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+
+#include <config.h>
+
+#ident "$Id$"
+
+#include <stddef.h>
+
+#include "memzero.h"
+
+
+extern inline void memzero(void *ptr, size_t size);
+extern inline void strzero(char *s);