simplify

packages/svelte/src/internal/client/reactivity/batch.js

@@ -342,18 +342,16 @@ export class Batch {
 			this.#deferred?.resolve();
 		}
 
+		var next_batch = /** @type {Batch | null} */ (/** @type {unknown} */ (current_batch));
+
 		// Order matters here - we need to commit and THEN continue flushing new batches, not the other way around,
 		// else we could start flushing a new batch and then, if it has pending work, rebase it right afterwards, which is wrong.
 		// In sync mode flushSync can cause #commit to wrongfully think that there needs to be a rebase, so we only do it in async mode
 		// TODO fix the underlying cause, otherwise this will likely regress when non-async mode is removed
 		if (async_mode_flag && !batches.has(this)) {
-			const prev = current_batch;
 			this.#commit();
-			current_batch = prev;
 		}
 
-		var next_batch = /** @type {Batch | null} */ (/** @type {unknown} */ (current_batch));
-
 		// Edge case: During traversal new branches might create effects that run immediately and set state,
 		// causing an effect and therefore a root to be scheduled again. We need to traverse the current batch
 		// once more in that case - most of the time this will just clean up dirty branches.