IB/mlx5_core: remove unreachable function call in module init

The call to mlx5_health_cleanup() in the module init function can never
be reached. Removing it.

Signed-off-by: Kleber Sacilotto de Souza <klebers@linux.vnet.ibm.com>
Acked-by: Eli Cohen <eli@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>