giopipe: output wake up on peer close
giopipe: output wake up on peer close

Similar to input is_readable(), return writable after a close, so an
error is reported to the async write.

Signed-off-by: Marc-André Lureau <a6f2b960a4aca61381fc650a67901b2ac8e83e6d@redhat.com>
Acked-by: Victor Toso <39b7599ff73bbf5db531748ba5250f21fa7120ff@redhat.com>

flexVDI/spice-gtk,flexVDI/spice-gtk