V4L/DVB (8906): v4l-dvb: fix assorted sparse warnings

Fix sparse warnings. None are serious, but cutting down on these helps find
future serious sparse warnings/errors.

Redid the av7710.c patch based on a suggestion by Oliver Endriss.

Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/dvb/frontends/dib7000m.c b/drivers/media/dvb/frontends/dib7000m.c
index 5f1375e..4de0fa9 100644
--- a/drivers/media/dvb/frontends/dib7000m.c
+++ b/drivers/media/dvb/frontends/dib7000m.c
@@ -1284,7 +1284,8 @@
 }
 EXPORT_SYMBOL(dib7000m_get_i2c_master);
 
-int dib7000m_i2c_enumeration(struct i2c_adapter *i2c, int no_of_demods, u8 default_addr, struct dib7000m_config cfg[])
+static int dib7000m_i2c_enumeration(struct i2c_adapter *i2c, int no_of_demods,
+		u8 default_addr, struct dib7000m_config cfg[])
 {
 	struct dib7000m_state st = { .i2c_adap = i2c };
 	int k = 0;