Partially apply suggestions from code review

Co-authored-by: str4d <thestr4d@gmail.com>

CHANGELOG.md

@@ -12,10 +12,11 @@ and this project adheres to Rust's notion of
   - `OutputsDisabled` 
 
 ### Changed
-- `orchard::builder::Builder::{add_spend, add_output}` now use 
-  concrete error types instead of `&'static str`s. 
-- `orchard::builder::Error` is now `BuildError` to differentiate from
-  new error types
+- `orchard::builder`:
+  - `Builder::{add_spend, add_output}` now use concrete error types instead of
+    `&'static str`s.
+  - `Error` has been renamed to `BuildError` to differentiate from new error
+    types.
 
 ## [0.3.0] - 2022-10-19
 ### Added

src/builder.rs

@@ -295,7 +295,7 @@ impl Builder {
         memo: Option<[u8; 512]>,
     ) -> Result<(), OutputsDisabled> {
         if !self.flags.outputs_enabled() {
-            return Err(());
+            return Err(OutputsDisabled);
         }
 
         self.recipients.push(RecipientInfo {