files: Do not close transport socket twice

We close it in sigreturn_restore() for unification with other
service fds, so kill the second close() from here.
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>

criu/files.c

@@ -1304,7 +1304,6 @@ int prepare_fds(struct pstree_item *me)
 
 	ret = open_fdinfos(me);
 
-	close_service_fd(TRANSPORT_FD_OFF);
 	if (rsti(me)->fdt)
 		futex_inc_and_wake(&rsti(me)->fdt->fdt_lock);
 out: