runtime/binary-port (close-binary-output-port): Close output chan.

runtime/binary-port (close-binary-output-port): Close output chan.

Close-binary-output-port was not closing the output channel of a
binary IO port when input and output channels were not the same
(e.g. when the port is the IO of a subprocess).  Close-binary-input-
port seemed to have the same thinko.