f without using "new" rust features

Author: TheBlueMatt

lightning/src/routing/router.rs

@@ -1117,8 +1117,8 @@ where L::Target: Logger {
 					// need it to increment at each hop by the fee charged at later hops. Further,
 					// we need to ensure we round up when we divide to get satoshis.
 					let channel_cap_msat = final_value_msat
-						.checked_mul(ROUTE_CAPACITY_PROVISION_FACTOR).map(|v| v.checked_add(aggregate_next_hops_fee_msat))
-						.flatten().unwrap_or(u64::max_value());
+						.checked_mul(ROUTE_CAPACITY_PROVISION_FACTOR).unwrap_or(u64::max_value())
+						.map(|v| v.checked_add(aggregate_next_hops_fee_msat)).unwrap_or(u64::max_value());
 					let channel_cap_sat = match channel_cap_msat.checked_add(999) {
 						None => break, // We overflowed above, just ignore this route hint
 						Some(val) => Some(val / 1000),