net/mlx5: Have single error unwinding path

Having multiple error unwinding path are error prone.
Lets have just one error unwinding path.

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