virtio_net: fix rx_drops stat for small pkts

We found the stat of rx drops for small pkts does not increment when
build_skb fail, it's not coherent with other mode's rx drops stat.
Signed-off-by: Wenliang Wang <wangwenliang.1995@bytedance.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/virtio_net.c

@@ -733,7 +733,7 @@ static struct sk_buff *receive_small(struct net_device *dev,
 		pr_debug("%s: rx error: len %u exceeds max size %d\n",
 			 dev->name, len, GOOD_PACKET_LEN);
 		dev->stats.rx_length_errors++;
-		goto err_len;
+		goto err;
 	}
 
 	if (likely(!vi->xdp_enabled)) {
@@ -825,10 +825,8 @@ static struct sk_buff *receive_small(struct net_device *dev,
 
 skip_xdp:
 	skb = build_skb(buf, buflen);
-	if (!skb) {
-		put_page(page);
+	if (!skb)
 		goto err;
-	}
 	skb_reserve(skb, headroom - delta);
 	skb_put(skb, len);
 	if (!xdp_prog) {
@@ -839,13 +837,12 @@ static struct sk_buff *receive_small(struct net_device *dev,
 	if (metasize)
 		skb_metadata_set(skb, metasize);
 
-err:
 	return skb;
 
 err_xdp:
 	rcu_read_unlock();
 	stats->xdp_drops++;
-err_len:
+err:
 	stats->drops++;
 	put_page(page);
 xdp_xmit: