!890 ethtool: ioctl: fix potential NULL deref in ethtool_set_coalesce()

Merge Pull Request from: @ci-robot 
 
PR sync from:  Zhengchao Shao <shaozhengchao@huawei.com>
 https://mailweb.openeuler.org/hyperkitty/list/kernel@openeuler.org/thread/RD4XA3AJYG55M6DKC5CSK5O2Z4JJWDPF/ 
 
 
Link:https://gitee.com/openeuler/kernel/pulls/890 

Reviewed-by: Jialin Zhang <zhangjialin11@huawei.com> 
Signed-off-by: Jialin Zhang <zhangjialin11@huawei.com> 

net/ethtool/ioctl.c

@@ -1696,7 +1696,7 @@ static noinline_for_stack int ethtool_set_coalesce(struct net_device *dev,
 	struct ethtool_coalesce coalesce;
 	int ret;
 
-	if (!dev->ethtool_ops->set_coalesce && !dev->ethtool_ops->get_coalesce)
+	if (!dev->ethtool_ops->set_coalesce || !dev->ethtool_ops->get_coalesce)
 		return -EOPNOTSUPP;
 
 	ret = dev->ethtool_ops->get_coalesce(dev, &coalesce, &kernel_coalesce,