splice: Add call to hsmd_{check,lock}_outpoint on mutual splice_locked

Author: ksedgwic

channeld/channeld.c

@@ -789,6 +789,9 @@ static void check_mutual_splice_locked(struct peer *peer)
 	status_debug("mutual splice_locked, channel updated to: %s",
 		     type_to_string(tmpctx, struct channel, peer->channel));
 
+	/* ensure the signer is locking at the same time */
+	lock_signer_outpoint(&inflight->outpoint);
+
 	msg = towire_channeld_got_splice_locked(NULL, inflight->amnt,
 						inflight->splice_amnt,
 						&inflight->outpoint.txid);

lightningd/channel_control.c

@@ -1283,7 +1283,8 @@ bool peer_start_channeld(struct channel *channel,
 				  | HSM_PERM_SIGN_REMOTE_TX
 				  | HSM_PERM_SIGN_ONCHAIN_TX
 				  | HSM_PERM_SIGN_CLOSING_TX
-				  | HSM_PERM_SIGN_SPLICE_TX);
+				  | HSM_PERM_SIGN_SPLICE_TX
+				  | HSM_PERM_LOCK_OUTPOINT);
 
 	channel_set_owner(channel,
 			  new_channel_subd(channel, ld,