net/i40e: fix flow director rule destroy

[ upstream commit 4fe1af8 ]

We should tear down the fdir when the last flow is destroyed, current
logic is opposite to expected behavior, this patch fixes this issue.

Fixes: 2e67a7f ("net/i40e: config flow director automatically")

Signed-off-by: Xiaolong Ye <xiaolong.ye@intel.com>
Acked-by: Beilei Xing <beilei.xing@intel.com>

drivers/net/i40e/i40e_flow.c

@@ -4743,7 +4743,7 @@ i40e_flow_destroy(struct rte_eth_dev *dev,
 		       &((struct i40e_fdir_filter *)flow->rule)->fdir, 0);
 
 		/* If the last flow is destroyed, disable fdir. */
-		if (!ret && !TAILQ_EMPTY(&pf->fdir.fdir_list)) {
+		if (!ret && TAILQ_EMPTY(&pf->fdir.fdir_list)) {
 			i40e_fdir_teardown(pf);
 			dev->data->dev_conf.fdir_conf.mode =
 				   RTE_FDIR_MODE_NONE;