virtio_ring: remove flags check for unmap packed indirect desc

When calling vring_unmap_desc_packed(), 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/20220224110402.108161-4-xuanzhuo@linux.alibaba.comSigned-off-by: Michael S. Tsirkin <mst@redhat.com>

drivers/virtio/virtio_ring.c

@@ -1009,19 +1009,11 @@ static void vring_unmap_desc_packed(const struct vring_virtqueue *vq,
 
 	flags = le16_to_cpu(desc->flags);
 
-	if (flags & VRING_DESC_F_INDIRECT) {
-		dma_unmap_single(vring_dma_dev(vq),
-				 le64_to_cpu(desc->addr),
-				 le32_to_cpu(desc->len),
-				 (flags & VRING_DESC_F_WRITE) ?
-				 DMA_FROM_DEVICE : DMA_TO_DEVICE);
-	} else {
 	dma_unmap_page(vring_dma_dev(vq),
 		       le64_to_cpu(desc->addr),
 		       le32_to_cpu(desc->len),
 		       (flags & VRING_DESC_F_WRITE) ?
 		       DMA_FROM_DEVICE : DMA_TO_DEVICE);
-	}
 }
 
 static struct vring_packed_desc *alloc_indirect_packed(unsigned int total_sg,