fixup! Refactor onion_utils to encrypt/decrypt OnionErrorPacket types

Author: joostjager

lightning/src/ln/onion_utils.rs

@@ -876,7 +876,7 @@ pub(super) fn crypt_failure_packet(shared_secret: &[u8], packet: &mut OnionError
 	process_chacha(&ammag, &mut packet.data);
 }
 
-pub(super) fn process_chacha(key: &[u8; 32], packet: &mut [u8]) {
+fn process_chacha(key: &[u8; 32], packet: &mut [u8]) {
 	let mut chacha = ChaCha20::new(key, &[0u8; 8]);
 	chacha.process_in_place(packet);
 }