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/aos/containers/resizeable_buffer.h b/aos/containers/resizeable_buffer.h
index b94f8cc..5eb955f 100644
--- a/aos/containers/resizeable_buffer.h
+++ b/aos/containers/resizeable_buffer.h
@@ -1,8 +1,7 @@
 #ifndef AOS_CONTAINERS_RESIZEABLE_BUFFER_H_
 #define AOS_CONTAINERS_RESIZEABLE_BUFFER_H_
 
-#include <stdlib.h>
-
+#include <cstdlib>
 #include <memory>
 
 #include "glog/logging.h"