net/mlx5: fix metering with flow ID 0
net/mlx5: fix metering with flow ID 0

When getting meter flow_id bits, there's an issue that not handling
correctly if flow_id is 0.

This fix this issue that when flow_id is 0, treat it as 1 bit.

Fixes: 83306d6c465a ("net/mlx5: fix meter statistics")
Cc: stable@dpdk.org

Signed-off-by: Shun Hao <d613c48229277bdb7e9f738ef1a173c538830b27@nvidia.com>
Acked-by: Matan Azrad <6969f5f553ad7652679a585a85d7321babc90464@nvidia.com>

john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk