scsi: megaraid_sas: replace instance->ctrl_context checks with instance->adapter_type

commit e7d36b88435077847e1ea992919c600f3fa9321c upstream.

Increase code readability. No functional change.

Signed-off-by: Kashyap Desai <kashyap.desai@broadcom.com>
Signed-off-by: Shivasharan S <shivasharan.srikanteshwara@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>