Fix fatal error in visualizerwip-gary

Whenever the visualizer encountered a SwitchToEvent, it generated the following
error:

Traceback (most recent call last):
  File "/home/mollison/bin/unit-trace", line 125, in <module>
    viz.visualizer.visualizer(stream3, nsec_time_per_maj)
  File "/home/mollison/bin/unit_trace/viz/visualizer.py", line 13, in visualizer
    sched.scan(time_per_maj)
  File "/home/mollison/bin/unit_trace/viz/schedule.py", line 253, in scan
    event.fill_span_event_from_start()
TypeError: unbound method fill_span_event_from_start() must be called with SwitchToEvent instance as first argument (got nothing instead)

1 files changed, 1 insertions, 1 deletions

diff --git a/unit_trace/viz/schedule.py b/unit_trace/viz/schedule.py
index ec6398d..542524b 100644
--- a/unit_trace/viz/schedule.py
+++ b/unit_trace/viz/schedule.py
@@ -250,7 +250,7 @@ class Schedule(object):
             for event in EVENT_LIST:
                 switch_event = switches[event]
                 if switch_event is not None:
-                    event.fill_span_event_from_start()
+                    switch_event.fill_span_event_from_start()
 
         # add events that correspond to the tasks and CPUS, at the very beginning
         self.time_slot_array.add_item_dummies(self)