V4L/DVB (8130): split dvb_ringbuffer dual-use functions

split the suckers into kernel-memory and user-memory versions,
annotate both properly.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
diff --git a/drivers/media/dvb/ttpci/av7110.c b/drivers/media/dvb/ttpci/av7110.c
index 6d7b9f6..dfe03cb 100644
--- a/drivers/media/dvb/ttpci/av7110.c
+++ b/drivers/media/dvb/ttpci/av7110.c
@@ -587,7 +587,7 @@
 		}
 		DVB_RINGBUFFER_SKIP(cibuf, 2);
 
-		dvb_ringbuffer_read(cibuf, av7110->debi_virt, len, 0);
+		dvb_ringbuffer_read(cibuf, av7110->debi_virt, len);
 
 		iwdebi(av7110, DEBINOSWAP, TX_LEN, len, 2);
 		iwdebi(av7110, DEBINOSWAP, IRQ_STATE_EXT, len, 2);