net/mlx5e: TC, fix return value check in mlx5e_tc_act_stats_create()

kvzalloc() returns NULL pointer not PTR_ERR() when it fails,
so replace the IS_ERR() check with NULL pointer check.

Fixes: d13674b1 ("net/mlx5e: TC, map tc action cookie to a hw counter")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Reviewed-by: Roi Dayan <roid@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

drivers/net/ethernet/mellanox/mlx5/core/en/tc/act_stats.c

@@ -37,7 +37,7 @@ mlx5e_tc_act_stats_create(void)
 	int err;
 
 	handle = kvzalloc(sizeof(*handle), GFP_KERNEL);
-	if (IS_ERR(handle))
+	if (!handle)
 		return ERR_PTR(-ENOMEM);
 
 	err = rhashtable_init(&handle->ht, &act_counters_ht_params);