tsocket: make sure we delete the fd event before calling close()

tsocket: make sure we delete the fd event before calling close()

We got random double free errors, when getting events from
epoll_wait() and try to dereference the private talloc pointer
attached to it.

Before doing the close() in the tstream_disconnect_send() function
we need to delete the fd event.

commit 38f505530ba06323a56c7d3914630efffcd12629 only fixed it for
tdgram sockets.

metze