net/mlx5: fix port matching in sample flow rule

net/mlx5: fix port matching in sample flow rule

If there are an explicit port match and sample action in the same flow,
mlx5 PMD pushes the explicit port match in the prefix subflow, and
uses the tag item match in the suffix subflow.

The explicit port match was translated into source vport match so
the sample suffix subflow lost this match after flow split.

This patch copies the explicit port match to the sample suffix subflow,
and the latter gets the correct source vport value in the flow matcher.

Fixes: b4c0ddbfcc58 ("net/mlx5: split sample flow into two sub-flows")
Cc: stable@dpdk.org
Signed-off-by: Jiawei Wang <jiaweiw@nvidia.com>
Acked-by: Viacheslav Ovsiienko <viacheslavo@nvidia.com>