Remove case that only exists for createBatch (#17506)

The comment says this is only needed for createBatch().commit() which
doesn't exist anymore.

Author: sebmarkbage

packages/react-reconciler/src/ReactFiberWorkLoop.js

@@ -978,82 +978,72 @@ function performSyncWorkOnRoot(root) {
   // Check if there's expired work on this root. Otherwise, render at Sync.
   const lastExpiredTime = root.lastExpiredTime;
   const expirationTime = lastExpiredTime !== NoWork ? lastExpiredTime : Sync;
-  if (root.finishedExpirationTime === expirationTime) {
-    // There's already a pending commit at this expiration time.
-    // TODO: This is poorly factored. This case only exists for the
-    // batch.commit() API.
-    commitRoot(root);
-  } else {
-    invariant(
-      (executionContext & (RenderContext | CommitContext)) === NoContext,
-      'Should not already be working.',
-    );
-
-    flushPassiveEffects();
-
-    // If the root or expiration time have changed, throw out the existing stack
-    // and prepare a fresh one. Otherwise we'll continue where we left off.
-    if (
-      root !== workInProgressRoot ||
-      expirationTime !== renderExpirationTime
-    ) {
-      prepareFreshStack(root, expirationTime);
-      startWorkOnPendingInteractions(root, expirationTime);
-    }
+  invariant(
+    (executionContext & (RenderContext | CommitContext)) === NoContext,
+    'Should not already be working.',
+  );
 
-    // If we have a work-in-progress fiber, it means there's still work to do
-    // in this root.
-    if (workInProgress !== null) {
-      const prevExecutionContext = executionContext;
-      executionContext |= RenderContext;
-      const prevDispatcher = pushDispatcher(root);
-      const prevInteractions = pushInteractions(root);
-      startWorkLoopTimer(workInProgress);
+  flushPassiveEffects();
 
-      do {
-        try {
-          workLoopSync();
-          break;
-        } catch (thrownValue) {
-          handleError(root, thrownValue);
-        }
-      } while (true);
-      resetContextDependencies();
-      executionContext = prevExecutionContext;
-      popDispatcher(prevDispatcher);
-      if (enableSchedulerTracing) {
-        popInteractions(((prevInteractions: any): Set<Interaction>));
-      }
+  // If the root or expiration time have changed, throw out the existing stack
+  // and prepare a fresh one. Otherwise we'll continue where we left off.
+  if (root !== workInProgressRoot || expirationTime !== renderExpirationTime) {
+    prepareFreshStack(root, expirationTime);
+    startWorkOnPendingInteractions(root, expirationTime);
+  }
 
-      if (workInProgressRootExitStatus === RootFatalErrored) {
-        const fatalError = workInProgressRootFatalError;
-        stopInterruptedWorkLoopTimer();
-        prepareFreshStack(root, expirationTime);
-        markRootSuspendedAtTime(root, expirationTime);
-        ensureRootIsScheduled(root);
-        throw fatalError;
-      }
+  // If we have a work-in-progress fiber, it means there's still work to do
+  // in this root.
+  if (workInProgress !== null) {
+    const prevExecutionContext = executionContext;
+    executionContext |= RenderContext;
+    const prevDispatcher = pushDispatcher(root);
+    const prevInteractions = pushInteractions(root);
+    startWorkLoopTimer(workInProgress);
 
-      if (workInProgress !== null) {
-        // This is a sync render, so we should have finished the whole tree.
-        invariant(
-          false,
-          'Cannot commit an incomplete root. This error is likely caused by a ' +
-            'bug in React. Please file an issue.',
-        );
-      } else {
-        // We now have a consistent tree. Because this is a sync render, we
-        // will commit it even if something suspended.
-        stopFinishedWorkLoopTimer();
-        root.finishedWork = (root.current.alternate: any);
-        root.finishedExpirationTime = expirationTime;
-        finishSyncRender(root, workInProgressRootExitStatus, expirationTime);
+    do {
+      try {
+        workLoopSync();
+        break;
+      } catch (thrownValue) {
+        handleError(root, thrownValue);
       }
+    } while (true);
+    resetContextDependencies();
+    executionContext = prevExecutionContext;
+    popDispatcher(prevDispatcher);
+    if (enableSchedulerTracing) {
+      popInteractions(((prevInteractions: any): Set<Interaction>));
+    }
 
-      // Before exiting, make sure there's a callback scheduled for the next
-      // pending level.
+    if (workInProgressRootExitStatus === RootFatalErrored) {
+      const fatalError = workInProgressRootFatalError;
+      stopInterruptedWorkLoopTimer();
+      prepareFreshStack(root, expirationTime);
+      markRootSuspendedAtTime(root, expirationTime);
       ensureRootIsScheduled(root);
+      throw fatalError;
     }
+
+    if (workInProgress !== null) {
+      // This is a sync render, so we should have finished the whole tree.
+      invariant(
+        false,
+        'Cannot commit an incomplete root. This error is likely caused by a ' +
+          'bug in React. Please file an issue.',
+      );
+    } else {
+      // We now have a consistent tree. Because this is a sync render, we
+      // will commit it even if something suspended.
+      stopFinishedWorkLoopTimer();
+      root.finishedWork = (root.current.alternate: any);
+      root.finishedExpirationTime = expirationTime;
+      finishSyncRender(root, workInProgressRootExitStatus, expirationTime);
+    }
+
+    // Before exiting, make sure there's a callback scheduled for the next
+    // pending level.
+    ensureRootIsScheduled(root);
   }
 
   return null;