V4L/DVB (5195): Frontends: make 4 functions static

This patch makes four needlessly global functions static.

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
diff --git a/drivers/media/dvb/frontends/stv0299.c b/drivers/media/dvb/frontends/stv0299.c
index 9348376..18768d2 100644
--- a/drivers/media/dvb/frontends/stv0299.c
+++ b/drivers/media/dvb/frontends/stv0299.c
@@ -92,7 +92,7 @@
 	return (ret != 1) ? -EREMOTEIO : 0;
 }
 
-int stv0299_write(struct dvb_frontend* fe, u8 *buf, int len)
+static int stv0299_write(struct dvb_frontend* fe, u8 *buf, int len)
 {
 	struct stv0299_state* state = fe->demodulator_priv;