MINOR: stconn/channel: Move CF_READ_DONTWAIT into the SC and rename it

The channel flag CF_READ_DONTWAIT is renamed to SC_FL_RCV_ONCE and moved
into the stream-connector.
diff --git a/src/peers.c b/src/peers.c
index 89e3bc7..fab92ee 100644
--- a/src/peers.c
+++ b/src/peers.c
@@ -1096,15 +1096,13 @@
 
 	/* initiate an outgoing connection */
 	s->scb->dst = addr;
-	s->scb->flags |= SC_FL_NOLINGER;
+	s->scb->flags |= (SC_FL_RCV_ONCE|SC_FL_NOLINGER);
 	s->flags = SF_ASSIGNED;
 	s->target = peer_session_target(peer, s);
 
 	s->do_log = NULL;
 	s->uniq_id = 0;
 
-	s->res.flags |= CF_READ_DONTWAIT;
-
 	_HA_ATOMIC_INC(&active_peers);
 	return 0;
 
@@ -3200,7 +3198,7 @@
 		}
 	}
 out:
-	sc_oc(sc)->flags |= CF_READ_DONTWAIT;
+	sc_opposite(sc)->flags |= SC_FL_RCV_ONCE;
 
 	if (curpeer)
 		HA_SPIN_UNLOCK(PEER_LOCK, &curpeer->lock);