BUG/MEDIUM: peers: resync ended with RESYNC_PARTIAL in wrong cases.

This bug was introduced with peers.c code re-work (7d0ceeec80):
"struct peer" flags are mistakenly checked instead of
"struct peers" flags to check the resync status of the local peer.

The issue was reported here:
   https://github.com/haproxy/haproxy/issues/545

This bug affects all branches >= 2.0 and should be backported.

(cherry picked from commit 70de43b77b10c6868b1ed42ac5439731ae6fa911)
Signed-off-by: Willy Tarreau <w@1wt.eu>
(cherry picked from commit 0c46a36711329375fb0b909d54614df7c65d511a)
Signed-off-by: Willy Tarreau <w@1wt.eu>
diff --git a/src/peers.c b/src/peers.c
index 3463671..1999d18 100644
--- a/src/peers.c
+++ b/src/peers.c
@@ -1027,13 +1027,13 @@
  * any other negative returned value must  be considered as an error with an appctx st0
  * returned value equal to PEER_SESS_ST_END.
  */
-static inline int peer_send_resync_finishedmsg(struct appctx *appctx, struct peer *peer)
+static inline int peer_send_resync_finishedmsg(struct appctx *appctx, struct peers *peers)
 {
 	struct peer_prep_params p = {
 		.control.head = { PEER_MSG_CLASS_CONTROL, },
 	};
 
-	p.control.head[1] = (peer->flags & PEERS_RESYNC_STATEMASK) == PEERS_RESYNC_FINISHED ?
+	p.control.head[1] = (peers->flags & PEERS_RESYNC_STATEMASK) == PEERS_RESYNC_FINISHED ?
 		PEER_MSG_CTRL_RESYNCFINISHED : PEER_MSG_CTRL_RESYNCPARTIAL;
 
 	return peer_send_msg(appctx, peer_prepare_control_msg, &p);
@@ -1950,7 +1950,7 @@
 	}
 
 	if ((peer->flags & PEER_F_TEACH_PROCESS) && !(peer->flags & PEER_F_TEACH_FINISHED)) {
-		repl = peer_send_resync_finishedmsg(appctx, peer);
+		repl = peer_send_resync_finishedmsg(appctx, peers);
 		if (repl <= 0)
 			return repl;