net/mlx5: change start pointer of compressed completion

net/mlx5: change start pointer of compressed completion

On a host having 128B cacheline size, some devices insert 64B padding in
each completion entry to avoid partial cacheline write by HW. But, as the
padding is ahead of completion data, casting a completion entry to
compressed mini-completions must start from the middle of the completion.

Signed-off-by: Yongseok Koh <yskoh@mellanox.com>
Acked-by: Shahaf Shuler <shahafs@mellanox.com>
Acked-by: Nelio Laranjeiro <nelio.laranjeiro@6wind.com>