{IB, net}/mlx5: No need to typecast from void* to mlx5_ib_dev*

Avoid typecasting from void* to mlx5_ib_dev* or mlx5e_rep_priv*
as it is not needed.

Signed-off-by: Parav Pandit <parav@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>