Revert "Fix invalid conversion in C++ code"

This reverts commit 4b4dfea25d.

include/string.h

@@ -10,11 +10,13 @@ void *
 __fortify_memcpy(void *dest, const void *src, size_t n)
 {
 	size_t bos = __builtin_object_size(dest, 0);
+	char *d = dest;
+	const char *s = src;
 
 	/* trap if pointers are overlapping but not if dest == src.
 	 * gcc seems to like to generate code that relies on dest == src */
-	if ((dest < src && dest + n > src) ||
-	    (src < dest && src + n > dest))
+	if ((d < s && d + n > s) ||
+	    (s < d && s + n > d))
 		__builtin_trap();
 	if (n > bos)
 		__builtin_trap();