[PATCH 3/6] mf/session: Fix backwards handling of MF_TOPONODE_NOSHUTDOWN_ON_REMOVE.

[Nikolay Sivov]

This might as well be correct, but we'll need a test. I think a simple 
graph with dummy source + grabber sink (not an activation object), will 
show this - setting topology, shutdown the session, check if some sink 
methods for MF_E_SHUTDOWN.