[media] e4000: rename some variables

Rename some variables.
Change error status checks from (ret < 0) to (ret).
No actual functionality changes.
Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>

drivers/media/tuners/e4000_priv.h

@@ -26,7 +26,7 @@
 #include <media/v4l2-subdev.h>
 #include <linux/regmap.h>
 
-struct e4000_priv {
+struct e4000 {
 	struct i2c_client *client;
 	struct regmap *regmap;
 	u32 clock;