MINOR: stream-int: don't touch polling anymore on shutdown

Not only it's become totally useless with muxes, in addition it's
dangerous to play with the mux's FD while shutting a stream down for
writes. It's already done *if necessary* by the cs_shutw() code at the
mux layer. Fortunately it doesn't seem to have any impact, most likely
the polling updates used to immediately revert this operation.
1 file changed