virtio_ring: remove flags check for unmap split indirect desc

When calling vring_unmap_one_split_indirect(), it will not encounter the
situation that the flags contains VRING_DESC_F_INDIRECT. So remove this
logic.
Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Link: https://lore.kernel.org/r/20220224110402.108161-3-xuanzhuo@linux.alibaba.comSigned-off-by: Michael S. Tsirkin <mst@redhat.com>

drivers/virtio/virtio_ring.c

@@ -379,19 +379,11 @@ static void vring_unmap_one_split_indirect(const struct vring_virtqueue *vq,
 
 	flags = virtio16_to_cpu(vq->vq.vdev, desc->flags);
 
-	if (flags & VRING_DESC_F_INDIRECT) {
-		dma_unmap_single(vring_dma_dev(vq),
-				 virtio64_to_cpu(vq->vq.vdev, desc->addr),
-				 virtio32_to_cpu(vq->vq.vdev, desc->len),
-				 (flags & VRING_DESC_F_WRITE) ?
-				 DMA_FROM_DEVICE : DMA_TO_DEVICE);
-	} else {
-		dma_unmap_page(vring_dma_dev(vq),
-			       virtio64_to_cpu(vq->vq.vdev, desc->addr),
-			       virtio32_to_cpu(vq->vq.vdev, desc->len),
-			       (flags & VRING_DESC_F_WRITE) ?
-			       DMA_FROM_DEVICE : DMA_TO_DEVICE);
-	}
+	dma_unmap_page(vring_dma_dev(vq),
+		       virtio64_to_cpu(vq->vq.vdev, desc->addr),
+		       virtio32_to_cpu(vq->vq.vdev, desc->len),
+		       (flags & VRING_DESC_F_WRITE) ?
+		       DMA_FROM_DEVICE : DMA_TO_DEVICE);
 }
 
 static unsigned int vring_unmap_one_split(const struct vring_virtqueue *vq,