NetRxPkt: Account buffer with ETH header in IOV length

In case of VLAN stripping ETH header is stored in a
separate chunk and length of IOV should take this into
account.

This patch fixes checksum validation for RX packets
with VLAN header.

Devices affected by this problem: e1000e and vmxnet3.

Cc: qemu-stable@nongnu.org
Signed-off-by: NDmitry Fleytman <dmitry@daynix.com>
Signed-off-by: NJason Wang <jasowang@redhat.com>

hw/net/net_rx_pkt.c

@@ -97,7 +97,7 @@ net_rx_pkt_pull_data(struct NetRxPkt *pkt,
         pkt->tot_len = iov_size(iov, iovcnt) - ploff + pkt->ehdr_buf_len;
         pkt->vec_len = iov_copy(pkt->vec + 1, pkt->vec_len_total - 1,
                                 iov, iovcnt, ploff,
-                                pkt->tot_len - pkt->ehdr_buf_len);
+                                pkt->tot_len - pkt->ehdr_buf_len) + 1;
     } else {
         net_rx_pkt_iovec_realloc(pkt, iovcnt);