net: hns3: remove unused hclgevf_cfg_func_mta_filter

The last patch apparently added a complete replacement for this
function, but left the old one in place, which now causes a
harmless warning:

drivers/net/ethernet/hisilicon/hns3/hns3vf/hclgevf_main.c:731:12: 'hclgevf_cfg_func_mta_filter' defined but not used

I assume it can be removed.

Fixes: 3a678b58

 ("net: hns3: Optimize the VF's process of updating multicast MAC")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>