scsi: bfa: Do not dereference port before it is null checked

Port is deferenced before it is null sanity checked, hence we
potentially have a null pointer dereference bug. Instead, initialise
trl_enabled from port->fcs->bfa after we are sure port is not null.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>