net/mlx5: fix metadata and meter split shared tag

net/mlx5: fix metadata and meter split shared tag

In the metadata flow split, PMD created the prefix subflow
with removed Queue or RSS action and appended the set tag and
copy table jump actions. If the flow being split for metadata
was the meter prefix subflow, the driver supposed to share the same
meter split tag action for the metadata split flow. There was the wrong
check for preceding meter split tag action, causing append with metadata
split set tag action and resulting the meter suffix subflow was missed
due to tag value mismatch.

This patch adds the checking before copying into extend action list,
to make sure the correct shared tag is used.

Fixes: 8d72fa668964 ("net/mlx5: share tag between meter and metadata")
Cc: stable@dpdk.org
Signed-off-by: Jiawei Wang <jiaweiw@nvidia.com>
Acked-by: Viacheslav Ovsiienko <viacheslavo@nvidia.com>