backlight: lm3639: Remove unnecessary return statements

Fixed the following checkpatch warning.

WARNING: void function return statements are not generally useful

Signed-off-by: Jingoo Han <[e-mail]>
Signed-off-by: Lee Jones <[e-mail]>

drivers/video/backlight/lm3639_bl.c

···
 	return;
 out:
 	dev_err(pchip->dev, "i2c failed to access register\n");
-	return;
 }
 
 /* flash */
···
 	return;
 out:
 	dev_err(pchip->dev, "i2c failed to access register\n");
-	return;
 }
 
 static const struct regmap_config lm3639_regmap = {