net: hns3: add a check for get_reset_level

driver inclusion
category: bugfix
bugzilla: NA
CVE: NA

Before calling get_reset_level, we should check whether it is NULL.

Feature or Bugfix:Bugfix

Signed-off-by: huangguangbin (A) <huangguangbin2@huawei.com>
Reviewed-by: xuzaibo <xuzaibo@huawei.com>
Reviewed-by: Yunsheng Lin <linyunsheng@huawei.com>
Reviewed-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>

drivers/net/ethernet/hisilicon/hns3/hns3_enet.c

@@ -2043,7 +2043,7 @@ static pci_ers_result_t hns3_slot_reset(struct pci_dev *pdev)
 
 	ops = ae_dev->ops;
 	/* request the reset */
-	if (ops->reset_event) {
+	if (ops->reset_event && ops->get_reset_level) {
 		if (!ae_dev->override_pci_need_reset) {
 			reset_type = ops->get_reset_level(ae_dev,
 						&ae_dev->hw_err_reset_req);