Replace use of deprecated C Standard library headers in C++ code.

Change-Id: I9fa6630c7e4bdb2897df34d417635d8c7d8253bc
Signed-off-by: Tyler Chatow <tchatow@gmail.com>
diff --git a/y2019/joystick_reader.cc b/y2019/joystick_reader.cc
index 7351130..a92dd90 100644
--- a/y2019/joystick_reader.cc
+++ b/y2019/joystick_reader.cc
@@ -1,9 +1,9 @@
-#include <math.h>
-#include <stdio.h>
-#include <string.h>
 #include <unistd.h>
 
 #include <chrono>
+#include <cmath>
+#include <cstdio>
+#include <cstring>
 
 #include "aos/actions/actions.h"
 #include "aos/init.h"