backlight: lm3630a: Return 0 on success in update_status functions

lm3630a_bank_a_update_status() and lm3630a_bank_b_update_status()
both return the brightness value if the brightness was successfully
updated. Writing to these attributes via sysfs would cause a 'Bad
address' error to be returned. These functions should return 0 on
success, so let's change it to correct that error.

Fixes: 28e64a6 ("backlight: lm3630: apply chip revision")
Signed-off-by: Brian Masney <masneyb@onstation.org>
Acked-by: Pavel Machek <pavel@ucw.cz>
Acked-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

drivers/video/backlight/lm3630a_bl.c

@@ -201,7 +201,7 @@ static int lm3630a_bank_a_update_status(struct backlight_device *bl)
 				      LM3630A_LEDA_ENABLE, LM3630A_LEDA_ENABLE);
 	if (ret < 0)
 		goto out_i2c_err;
-	return bl->props.brightness;
+	return 0;
 
 out_i2c_err:
 	dev_err(pchip->dev, "i2c failed to access\n");
@@ -278,7 +278,7 @@ static int lm3630a_bank_b_update_status(struct backlight_device *bl)
 				      LM3630A_LEDB_ENABLE, LM3630A_LEDB_ENABLE);
 	if (ret < 0)
 		goto out_i2c_err;
-	return bl->props.brightness;
+	return 0;
 
 out_i2c_err:
 	dev_err(pchip->dev, "i2c failed to access REG_CTRL\n");