net: hns3: Remove redundant codes of query advertised flow control abilitiy

If the advertised flow control ability has been fetched using
phy_ethtool_ksettings_get() or hclge_get_link_mode() then it is
unnecessary to fetch them again later using hclge_get_flowctrl_adv().
This patch removes it.

Signed-off-by: Jian Shen <shenjian15@huawei.com>
Signed-off-by: Peng Li <lipeng321@huawei.com>
Signed-off-by: Salil Mehta <salil.mehta@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>