Don't use ok_or_else, cleanups

Author: aerooneqq

compiler/rustc_ast_lowering/src/delegation/attributes.rs

@@ -65,22 +65,21 @@ impl<'hir> LoweringContext<'_, 'hir> {
     ) -> Vec<hir::Attribute> {
         ADDITIONS
             .iter()
-            .filter_map(|addition_info| {
-                if existing.is_some_and(|attrs| attrs.iter().any(|a| (addition_info.equals)(a))) {
-                    return None;
-                }
-
-                match addition_info.kind {
-                    AdditionKind::Default { factory } => Some(factory(span)),
-                    AdditionKind::Inherit { factory, .. } =>
-                    {
-                        #[allow(deprecated)]
-                        self.tcx
-                            .get_all_attrs(sig_id)
-                            .iter()
-                            .find_map(|a| (addition_info.equals)(a).then(|| factory(span, a)))
-                    }
-                }
+            .filter_map(|addition| {
+                existing
+                    .is_none_or(|attrs| !attrs.iter().any(|a| (addition.equals)(a)))
+                    .then(|| match addition.kind {
+                        AdditionKind::Default { factory } => Some(factory(span)),
+                        AdditionKind::Inherit { factory, .. } =>
+                        {
+                            #[allow(deprecated)]
+                            self.tcx
+                                .get_all_attrs(sig_id)
+                                .iter()
+                                .find_map(|a| (addition.equals)(a).then(|| factory(span, a)))
+                        }
+                    })
+                    .flatten()
             })
             .collect::<Vec<_>>()
     }

compiler/rustc_ast_lowering/src/delegation/resolution.rs

@@ -214,9 +214,11 @@ impl<'tcx, T: LoweringContextForResolution<'tcx>> DelegationResolverForLowering<
 
         // If there are definitions inside and we can't delete target expression, then report an error.
         // FIXME(fn_delegation): support deletion of target expression with defs inside.
-        (should_generate_block || !contains_defs).ok_or_else(|| {
-            tcx.dcx().emit_err(DelegationAttemptedBlockWithDefsDeletion { span: block.span })
-        })
+        if should_generate_block || !contains_defs {
+            Ok(())
+        } else {
+            Err(tcx.dcx().emit_err(DelegationAttemptedBlockWithDefsDeletion { span: block.span }))
+        }
     }
 
     fn should_generate_block(