virtio-net: fix offload ctrl endian

Spec said offloads should be le64, so use virtio_ldq_p() to guarantee
valid endian.

Fixes: 644c9858 ("virtio-net: dynamic network offloads configuration")
Cc: qemu-stable@nongnu.org
Cc: Dmitry Fleytman <dfleytma@redhat.com>
Signed-off-by: NJason Wang <jasowang@redhat.com>
(cherry picked from commit 189ae6bb)
Signed-off-by: NMichael Roth <mdroth@linux.vnet.ibm.com>

hw/net/virtio-net.c

@@ -723,6 +723,8 @@ static int virtio_net_handle_offloads(VirtIONet *n, uint8_t cmd,
     if (cmd == VIRTIO_NET_CTRL_GUEST_OFFLOADS_SET) {
         uint64_t supported_offloads;
 
+        offloads = virtio_ldq_p(vdev, &offloads);
+
         if (!n->has_vnet_hdr) {
             return VIRTIO_NET_ERR;
         }