net/hns3: fix config when creating RSS rule after flush

net/hns3: fix config when creating RSS rule after flush

Currnetly, when user create a flow RSS rule and then flush the rule, driver
will set 0 for the internal structure of hw->rss_info maintained in driver.
And then user create a flow RSS rule without specified RSS hash key, driver
configure a validate RSS hash key into hardware network engine and will
cause an RSS error. The related steps when using testpmd as
follows:
  flow 0 <pattern> action rss xx end / end
  flow flush 0
  flow 0 <pattern> action rss queues 0 1 end / end

To slove the preceding problem, the flow flush processing is modified.
it don't clear all RSS configurations for hw->rss_info. Actually the RSS
key information in the hardware is not cleared, therefore, the
hw->rss_info.key is kept consistent with the value in the hardware. In
addition, because reset the redirection table, we need to set queues NULL
and queue_num for zero that indicate the corresponding parameters in the
hardware is unavailable. Also we set hw->rss_info.func to
RTE_ETH_HASH_FUNCTION_MAX that indicate it is invalid.

Fixes: c37ca66f2b27 ("net/hns3: support RSS")
Cc: stable@dpdk.org
Signed-off-by: Lijun Ou <oulijun@huawei.com>
Signed-off-by: Wei Hu (Xavier) <xavier.huwei@huawei.com>