megaraid_sas: Downgrade two success messages to info

I actually read the error messages in my logs, and successful
initialization is not an error.

Arguably these log lines could be deleted entirely.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Reviewed-by: Hannes Reinicke <hare@suse.de>
Acked-by: Sumit Saxena <sumit.saxena@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>