[media] c8sectpfe: Fix broken circular buffer wp management

During the review process, a regression was intoduced in the
circular buffer write pointer management. This means that wp
doesn't get managed properly once the buffer becomes full.
Signed-off-by: Peter Griffin <peter.griffin@linaro.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

drivers/media/platform/sti/c8sectpfe/c8sectpfe-core.c

@@ -130,7 +130,7 @@ static void channel_swdemux_tsklet(unsigned long data)
 		writel(channel->back_buffer_busaddr, channel->irec +
 			DMA_PRDS_BUSRP_TP(0));
 	else
-		writel(wp, channel->irec + DMA_PRDS_BUSWP_TP(0));
+		writel(wp, channel->irec + DMA_PRDS_BUSRP_TP(0));
 }
 
 static int c8sectpfe_start_feed(struct dvb_demux_feed *dvbdmxfeed)