net: hns3: dump some debug information when reset fail

When reset fails, there is some information that will help for
finding out why does reset fail. and removes an unused
core_rst_cnt field in struct hclge_rst_stats.

Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>