Used new WPILIB2015 macro to mark differences with the old WPILib.

Change-Id: I9e45a22096bdb108f74f9dc341037d5f64506ff5
diff --git a/y2014/wpilib/wpilib_interface.cc b/y2014/wpilib/wpilib_interface.cc
index ffb10e2..1e70fb2 100644
--- a/y2014/wpilib/wpilib_interface.cc
+++ b/y2014/wpilib/wpilib_interface.cc
@@ -235,7 +235,12 @@
     LOG(INFO, "In sensor reader thread\n");
 
     my_pid_ = getpid();
-    ds_ = DriverStation::GetInstance();
+    ds_ =
+#ifdef WPILIB2015
+        DriverStation::GetInstance();
+#else
+        &DriverStation::GetInstance();
+#endif
 
     top_reader_.Start();
     bottom_reader_.Start();