net: hns: optimizate fmt of snprintf()

It misses string format in function snprintf(), as below:
snprintf(buff, ETH_GSTRING_LEN, g_gmac_stats_string[i].desc);

It needs to add "%s" to fix it as below:
snprintf(buff, ETH_GSTRING_LEN, "%s", g_gmac_stats_string[i].desc);

Signed-off-by: Qianqian Xie <xieqianqian@huawei.com>
Signed-off-by: Kejian Yan <yankejian@huawei.com>
Signed-off-by: Yisen Zhuang <Yisen.Zhuang@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/hisilicon/hns/hns_dsaf_gmac.c

@@ -664,7 +664,8 @@ static void hns_gmac_get_strings(u32 stringset, u8 *data)
 		return;
 
 	for (i = 0; i < ARRAY_SIZE(g_gmac_stats_string); i++) {
-		snprintf(buff, ETH_GSTRING_LEN, g_gmac_stats_string[i].desc);
+		snprintf(buff, ETH_GSTRING_LEN, "%s",
+			 g_gmac_stats_string[i].desc);
 		buff = buff + ETH_GSTRING_LEN;
 	}
 }