MINOR: session: call the socket layer init function when a session establishes

In sess_establish, once we've prepared everythin, we can call the socket layer
init function. We pass an argument for targets which have one (eg: servers). At
the moment, the existing socket layers don't have init functions, but SSL will
need one.

src/session.c

@@ -717,6 +717,14 @@ static void sess_establish(struct session *s, struct stream_interface *si)
 		rep->rto = s->be->timeout.server;
 	}
 	req->wex = TICK_ETERNITY;
+
+	if (si->sock.init) {
+		/* initialize the socket layer if needed */
+		void *arg = NULL;
+		if (target_srv(&s->target))
+			arg = target_srv(&s->target)->sock_init_arg;
+		si->sock.init(si, arg);
+	}
 }
 
 /* Update stream interface status for input states SI_ST_ASS, SI_ST_QUE, SI_ST_TAR.