net/nfp: fix switch domain free check

[ upstream commit 5b1b9f9c11bedb672cdf01c834d6c341d50a0f1e ]

CI found calling 'rte_eth_switch_domain_free()' without checking return
value.

Coverity issue: 414936
Fixes: 20eaa8e2ebae ("net/nfp: free switch domain ID on close")

Signed-off-by: Chaoyong He <chaoyong.he@corigine.com>
Reviewed-by: Long Wu <long.wu@corigine.com>
Reviewed-by: Peng Zhang <peng.zhang@corigine.com>

drivers/net/nfp/flower/nfp_flower.c

@@ -1176,7 +1176,8 @@ nfp_uninit_app_fw_flower(struct nfp_pf_dev *pf_dev)
 	nfp_cpp_area_free(pf_dev->ctrl_area);
 	rte_free(app_fw_flower->pf_hw);
 	nfp_flow_priv_uninit(pf_dev);
-	rte_eth_switch_domain_free(app_fw_flower->switch_domain_id);
+	if (rte_eth_switch_domain_free(app_fw_flower->switch_domain_id) != 0)
+		PMD_DRV_LOG(WARNING, "Failed to free switch domain for device");
 	rte_free(app_fw_flower);
 }