mlx4_core: Avoid double free_icms

On the error path of mlx4_init_hca(), mlx4_close_hca() is called,
followed by mlx4_free_icms() and mlx4_UNMAP_FA().  But both those
functions are also called from mlx4_close_hca(), which leads to a
double free.

Signed-off-by: Yevgeny Petrilin <yevgenyp@mellanox.co.il>
Signed-off-by: Roland Dreier <rolandd@cisco.com>