net/mlx5: use kvfree() for memory allocated with kvzalloc()

It is allocated with kvzalloc(), the corresponding release function
should not be kfree(), use kvfree() instead.

Generated by: scripts/coccinelle/api/kfree_mismatch.cocci

Signed-off-by: Junlin Yang <yangjunlin@yulong.com>
Reviewed-by: Roi Dayan <roid@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>