net: hns3: fix dereference of ae_dev before it is null checked

driver inclusion
category: bugfix
bugzilla: NA
CVE: NA

Pointer ae_dev is null checked however, prior to that it is dereferenced
when assigned pointer ops. Fix this by assigning pointer ops after ae_dev
has been null checked.

Addresses-Coverity: ("Dereference before null check")
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Signed-off-by: Nliweihang <liweihang@huawei.com>
Reviewed-by: Nlipeng <lipeng321@huawei.com>
Reviewed-by: NYang Yingliang <yangyingliang@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

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

@@ -2035,13 +2035,14 @@ static pci_ers_result_t hns3_error_detected(struct pci_dev *pdev,
 static pci_ers_result_t hns3_slot_reset(struct pci_dev *pdev)
 {
 	struct hnae3_ae_dev *ae_dev = pci_get_drvdata(pdev);
-	const struct hnae3_ae_ops *ops = ae_dev->ops;
+	const struct hnae3_ae_ops *ops;
 	enum hnae3_reset_type reset_type;
 	struct device *dev = &pdev->dev;
 
 	if (!ae_dev || !ae_dev->ops)
 		return PCI_ERS_RESULT_NONE;
 
+	ops = ae_dev->ops;
 	/* request the reset */
 	if (ops->reset_event) {
 		if (!ae_dev->override_pci_need_reset) {