Fix a syntax error in examples (movie_demo.py).

Author: mgiuca-google

examples/animation/old_animation/movie_demo.py

@@ -49,7 +49,7 @@
     # This is a quick and dirty check; it leaves some spurious output
     # for the user to puzzle over.
 except OSError:
-    print not_found_msg
+    print(not_found_msg)
     sys.exit("quitting\n")