Don't wait for "prepare" stage of every peer's fd. Just
send everything to a peer's global transport socket, and
the peer will find appropriate fd, it needs at the moment.

travis-ci: success for Rework file opening scheme to make it asynchronous (rev5)
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: Pavel Emelyanov <xemul@virtuozzo.com>