The vf id from ethtool is added 1 before configured to driver.
So it's necessary to minus 1 when printing it, in order to
keep consistent with user's configuration.

Fixes: dd74f815 ("net: hns3: Add support for rule add/delete for flow director")
Signed-off-by: Jian Shen <shenjian15@huawei.com>
Signed-off-by: Guangbin Huang <huangguangbin2@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>