Make sure that the internal strdup is used.

The kernel strdup will still be used, as the local symbol doesn't
override that. Since we must not use strdup from within the kernel
debugger (as it does malloc from the normal heap), force the use of
the internal strdup that gets redirected to debug_malloc.

src/add-ons/kernel/debugger/qrencode/split.c

@@ -41,7 +41,7 @@
 
 #if !HAVE_STRDUP
 #undef strdup
-char *strdup(const char *s)
+char *strdup_internal(const char *s)
 {
 	size_t len = strlen(s) + 1;
 	void *new = malloc(len);
@@ -269,7 +269,7 @@ static char *dupAndToUpper(const char *str, QRencodeMode hint)
 	char *newstr, *p;
 	QRencodeMode mode;
 
-	newstr = strdup(str);
+	newstr = strdup_internal(str);
 	if(newstr == NULL) return NULL;
 
 	p = newstr;