net/mlx5: HWS, use the right size when writing arg data

When writing arg data, wrong size was used - fixing this.

Signed-off-by: Yevgeny Kliteynik <kliteyn@nvidia.com>
Reviewed-by: Itamar Gozlan <igozlan@nvidia.com>
Reviewed-by: Mark Bloch <mbloch@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
Link: https://patch.msgid.link/20250102181415.1477316-14-tariqt@nvidia.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>