f clarify comment

Author: TheBlueMatt

lightning/src/ln/chanmon_update_fail_tests.rs

@@ -3159,7 +3159,7 @@ fn do_test_inverted_mon_completion_order(complete_bc_commitment_dance: bool) {
 
 		// At this point node B still hasn't persisted the `ChannelMonitorUpdate` with the
 		// preimage in the A <-> B channel, which will prevent it from persisting the
-		// `ChannelMonitorUpdate` here to avoid "losing" the preimage.
+		// `ChannelMonitorUpdate` for the B<->C channel here to avoid "losing" the preimage.
 		nodes[1].node.handle_revoke_and_ack(&nodes[2].node.get_our_node_id(), &cs_raa);
 		check_added_monitors(&nodes[1], 0);
 		assert!(nodes[1].node.get_and_clear_pending_msg_events().is_empty());