fix pydotprint when the mode is profilemode but the fct have not been called.

theano/printing.py

@@ -375,7 +375,7 @@ def pydotprint(fct, outfile=os.path.join(config.compiledir,'theano.pydotprint.pn
     blue ellipse are output of the graph
     grey ellipse are var generated by the graph that are not output and are not used.
     """
-    if not isinstance(mode,ProfileMode):
+    if not isinstance(mode,ProfileMode) or not mode.fct_call.has_key(fct):
         mode=None
     try:
         import pydot as pd