net/mlx5: SF, use recent sysfs api

Use sysfs_emit() which is aware of PAGE_SIZE buffer.
Signed-off-by: NParav Pandit <parav@nvidia.com>
Signed-off-by: NSaeed Mahameed <saeedm@nvidia.com>

drivers/net/ethernet/mellanox/mlx5/core/sf/dev/dev.c

@@ -39,7 +39,7 @@ static ssize_t sfnum_show(struct device *dev, struct device_attribute *attr, cha
 	struct auxiliary_device *adev = container_of(dev, struct auxiliary_device, dev);
 	struct mlx5_sf_dev *sf_dev = container_of(adev, struct mlx5_sf_dev, adev);
 
-	return scnprintf(buf, PAGE_SIZE, "%u\n", sf_dev->sfnum);
+	return sysfs_emit(buf, "%u\n", sf_dev->sfnum);
 }
 static DEVICE_ATTR_RO(sfnum);