net: hns3: fix aRFS FD rules leftover after add a user FD rule

When user had created a FD rule, all the aRFS rules should be clear up.
HNS3 process flow as below:
1.get spin lock of fd_ruls_list
2.clear up all aRFS rules
3.release lock
4.get spin lock of fd_ruls_list
5.creat a rules
6.release lock;

There is a short period of time between step 3 and step 4, which would
creatting some new aRFS FD rules if driver was receiving packet.
So refactor the fd_rule_lock to fix it.

Fixes: 44122887

 ("net: hns3: refine the flow director handle")
Signed-off-by: Guojia Liao <liaoguojia@huawei.com>
Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>