connectd: demote "Peer did not close, forcing close" to UNUSUAL

This message is logged when connectd tries to shut down a peer
connection but the transmit buffer remains full for too long, maybe
because the peer has crashed or has lost connectivity. Logging this
message at the BROKEN level is inappropriate because BROKEN is intended
to flag logic errors that imply incorrect code in CLN. The error in
question here is actually a runtime error, which does not imply
incorrect code (at least on our side), so demote the log message to the
UNUSUAL level. (Even this is still probably too severe, as this message
is logged rather more frequently than "unusual" would suggest.)

Changelog-None
Closes: #5678

Author: whitslack

connectd/multiplex.c

@@ -106,8 +106,7 @@ static void maybe_free_peer(struct peer *peer)
  * not reading, we have to give up. */
 static void close_peer_io_timeout(struct peer *peer)
 {
-	/* BROKEN means we'll trigger CI if we see it, though it's possible */
-	status_peer_broken(&peer->id, "Peer did not close, forcing close");
+	status_peer_unusual(&peer->id, CI_UNEXPECTED "Peer did not close, forcing close");
 	io_close(peer->to_peer);
 }