qed: Fix a error code in qed_hw_init()

If the qed_fw_overlay_mem_alloc() then we should return -ENOMEM instead
of success.

Fixes: 30d5f858

 ("qed: FW 8.42.2.0 Add fw overlay feature")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>