Removed incorrect .return accessor from captureCommitPhaseErrorForUnmountedFiber()

Author: Brian Vaughn

packages/react-reconciler/src/ReactFiberWorkLoop.new.js

@@ -3170,7 +3170,7 @@ export function captureCommitPhaseErrorForUnmountedFiber(
   nearestMountedAncestor: Fiber,
   error: mixed,
 ) {
-  let fiber = nearestMountedAncestor.return;
+  let fiber = nearestMountedAncestor;
   while (fiber !== null) {
     if (fiber.tag === HostRoot) {
       captureCommitPhaseErrorOnRoot(fiber, sourceFiber, error);

packages/react-reconciler/src/__tests__/ReactHooksWithNoopRenderer-test.js

@@ -2355,7 +2355,7 @@ describe('ReactHooksWithNoopRenderer', () => {
               return <span prop="ErrorBoundary fallback" />;
             }
             Scheduler.unstable_yieldValue('ErrorBoundary render success');
-            return this.props.children;
+            return this.props.children || null;
           }
         };
 
@@ -2377,7 +2377,7 @@ describe('ReactHooksWithNoopRenderer', () => {
             Scheduler.unstable_yieldValue(
               'DerivedStateOnlyErrorBoundary render success',
             );
-            return this.props.children;
+            return this.props.children || null;
           }
         };
 
@@ -2389,7 +2389,7 @@ describe('ReactHooksWithNoopRenderer', () => {
           }
           render() {
             Scheduler.unstable_yieldValue(`LogOnlyErrorBoundary render`);
-            return this.props.children;
+            return this.props.children || null;
           }
         };
       });
@@ -2551,18 +2551,10 @@ describe('ReactHooksWithNoopRenderer', () => {
 
       // @gate new
       it('should use the nearest still-mounted boundary if there are no unmounted boundaries', () => {
-        function Conditional({showChildren}) {
-          if (showChildren) {
-            return <BrokenUseEffectCleanup />;
-          } else {
-            return null;
-          }
-        }
-
         act(() => {
           ReactNoop.render(
             <LogOnlyErrorBoundary>
-              <Conditional showChildren={true} />
+              <BrokenUseEffectCleanup />
             </LogOnlyErrorBoundary>,
           );
         });
@@ -2573,11 +2565,7 @@ describe('ReactHooksWithNoopRenderer', () => {
         ]);
 
         act(() => {
-          ReactNoop.render(
-            <LogOnlyErrorBoundary>
-              <Conditional showChildren={false} />
-            </LogOnlyErrorBoundary>,
-          );
+          ReactNoop.render(<LogOnlyErrorBoundary />);
         });
 
         expect(Scheduler).toHaveYielded([