Fix signature of new_vlan_client

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

net.h

@@ -73,7 +73,8 @@ struct VLANState {
 
 VLANState *qemu_find_vlan(int id, int allocate);
 VLANClientState *qemu_find_netdev(const char *id);
-VLANClientState *qemu_new_vlan_client(VLANState *vlan,
+VLANClientState *qemu_new_vlan_client(net_client_type type,,
+                                      VLANState *vlan,
                                       VLANClientState *peer,
                                       const char *model,
                                       const char *name,