f tick and clarify

Author: TheBlueMatt

lightning/src/ln/channelmanager.rs

@@ -4457,8 +4457,7 @@ impl<M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelManager<M, T, K, F
 				}],
 			};
 			// We update the ChannelMonitor on the backward link, after
-			// receiving an offchain preimage event from the forward link (the
-			// event being update_fulfill_htlc).
+			// receiving an `update_fulfill_htlc` from the forward link.
 			let update_res = self.chain_monitor.update_channel(prev_hop.outpoint, preimage_update);
 			if update_res != ChannelMonitorUpdateStatus::Completed {
 				// TODO: This needs to be handled somehow - if we receive a monitor update