lastStageGain gets recalculated unconditionally even though it is the stageGain of the last stage. Refactor for increased simplicity and efficiency. Signed-off-by: Stefan Klug <stefan.klug@ideasonboard.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com> Reviewed-by: Daniel Scally <dan.scally@ideasonboard.com> Reviewed-by: Paul Elder <paul.elder@ideasonboard.com> Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>