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/frc971/control_loops/drivetrain/drivetrain.cc b/frc971/control_loops/drivetrain/drivetrain.cc
index 5242550..2cc9f35 100644
--- a/frc971/control_loops/drivetrain/drivetrain.cc
+++ b/frc971/control_loops/drivetrain/drivetrain.cc
@@ -1,9 +1,9 @@
 #include "frc971/control_loops/drivetrain/drivetrain.h"
 
 #include <sched.h>
-#include <stdio.h>
 
 #include <cmath>
+#include <cstdio>
 #include <memory>
 
 #include "Eigen/Dense"