scsi: megaraid_sas: Do not kill host bus adapter, if adapter is already dead

Link: https://lore.kernel.org/r/1579000882-20246-5-git-send-email-anand.lodnoor@broadcom.com


Signed-off-by: Shivasharan S <shivasharan.srikanteshwara@broadcom.com>
Signed-off-by: Anand Lodnoor <anand.lodnoor@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>