IB/mlx5: Fix memory leak in query device

We need to free dev->port when we fail to enable RoCE or
initialize node data.

Fixes: 0837e86a

 ('IB/mlx5: Add per port counters')
Signed-off-by: Majd Dibbiny <majd@mellanox.com>
Signed-off-by: Maor Gottlieb <maorg@mellanox.com>
Reviewed-by: Mark Bloch <markb@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>