Switch Spline UI to use images

Change-Id: I6b537b2fd1d0a572e9fc2560065cd9f039974164
Signed-off-by: Ravago Jones <ravagojones@gmail.com>
diff --git a/frc971/control_loops/python/spline_graph.py b/frc971/control_loops/python/spline_graph.py
index e57b64a..347837b 100755
--- a/frc971/control_loops/python/spline_graph.py
+++ b/frc971/control_loops/python/spline_graph.py
@@ -119,7 +119,7 @@
         self.file_name_box = Gtk.Entry()
         self.file_name_box.set_size_request(200, 40)
 
-        self.file_name_box.set_text(FIELD.json_name)
+        self.file_name_box.set_text(FIELD.field_id + ".json")
         self.file_name_box.set_editable(True)
 
         container.put(self.file_name_box, 0, 0)