io_uring: clean up io_req_free_batch_finish()

io_req_free_batch_finish() is final and does not permit struct req_batch
to be reused without re-init. To be more consistent don't clear ->task
there.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

fs/io_uring.c

@@ -2397,10 +2397,8 @@ static inline void io_init_req_batch(struct req_batch *rb)
 static void io_req_free_batch_finish(struct io_ring_ctx *ctx,
 				     struct req_batch *rb)
 {
-	if (rb->task) {
+	if (rb->task)
 		io_put_task(rb->task, rb->task_refs);
-		rb->task = NULL;
-	}
 	if (rb->ctx_refs)
 		percpu_ref_put_many(&ctx->refs, rb->ctx_refs);
 }