splice: Let RPC stfu take time

Before we would fail the RPC stfu request if there were pending changes preventing immediate stfu.

Now we relax the policy to allow eventual stfu once the pending changes complete.

Author: ddustin

channeld/channeld.c

@@ -5061,15 +5061,9 @@ static void handle_stfu_req(struct peer *peer, const u8 *inmsg)
 	peer->stfu_initiator = LOCAL;
 	peer->want_stfu = true;
 
-	if (!maybe_send_stfu(peer)) {
-		msg = towire_channeld_splice_state_error(NULL, tal_fmt(tmpctx,
-							 "Pending updates"
-							 " prevent us from STFU"
-							 " mode at this"
-							 " time."));
-		wire_sync_write(MASTER_FD, take(msg));
-		return;
-	}
+	/* If the `stfu` cant be sent now it will be sent when the current
+	 * pending actions are completed. */
+	maybe_send_stfu(peer);
 }
 
 static void handle_abort_req(struct peer *peer, const u8 *inmsg)