libc: io: implement (v)fprintf

lib/libc/io/stdio/printf.c

@@ -5,7 +5,7 @@ int printf(const char *format, ...)
 {
 	va_list arg;
 	va_start(arg, format);
-	int ret = vprintf(format, arg);
+	int ret = vfprintf(stdout, format, arg);
 	va_end(arg);
 
 	return ret;