virtio_net: small: remove skip_xdp

Because the skb build code is not shared between xdp and non-xdp, and
the xdp code in receive_small() is simpler, so "skip_xdp" is not needed.
We can remove it.
Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/virtio_net.c

@@ -1028,13 +1028,12 @@ static struct sk_buff *receive_small(struct net_device *dev,
 				     unsigned int *xdp_xmit,
 				     struct virtnet_rq_stats *stats)
 {
-	struct sk_buff *skb;
-	struct bpf_prog *xdp_prog;
 	unsigned int xdp_headroom = (unsigned long)ctx;
 	struct page *page = virt_to_head_page(buf);
 	unsigned int header_offset;
 	unsigned int headroom;
 	unsigned int buflen;
+	struct sk_buff *skb;
 
 	len -= vi->hdr_len;
 	stats->bytes += len;
@@ -1046,22 +1045,21 @@ static struct sk_buff *receive_small(struct net_device *dev,
 		goto err;
 	}
 
-	if (likely(!vi->xdp_enabled)) {
-		xdp_prog = NULL;
-		goto skip_xdp;
-	}
+	if (unlikely(vi->xdp_enabled)) {
+		struct bpf_prog *xdp_prog;
 
-	rcu_read_lock();
-	xdp_prog = rcu_dereference(rq->xdp_prog);
-	if (xdp_prog) {
-		skb = receive_small_xdp(dev, vi, rq, xdp_prog, buf, xdp_headroom,
-					len, xdp_xmit, stats);
+		rcu_read_lock();
+		xdp_prog = rcu_dereference(rq->xdp_prog);
+		if (xdp_prog) {
+			skb = receive_small_xdp(dev, vi, rq, xdp_prog, buf,
+						xdp_headroom, len, xdp_xmit,
+						stats);
+			rcu_read_unlock();
+			return skb;
+		}
 		rcu_read_unlock();
-		return skb;
 	}
-	rcu_read_unlock();
 
-skip_xdp:
 	header_offset = VIRTNET_RX_PAD + xdp_headroom;
 	headroom = vi->hdr_len + header_offset;
 	buflen = SKB_DATA_ALIGN(GOOD_PACKET_LEN + headroom) +