drivers/video/backlight/lcd.c: return ENXIO when ops functions cannot be called

Previously, when ops functions cannot be called, lcd_show_contrast() and
lcd_store_contrast() returned 0, instead of ENXIO.

Thus, in this case, a local variable 'rc' for return value should be
initialized as ENXIO, after kstrtoul() is called.
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/video/backlight/lcd.c

@@ -108,7 +108,7 @@ static ssize_t lcd_show_power(struct device *dev, struct device_attribute *attr,
 static ssize_t lcd_store_power(struct device *dev,
 		struct device_attribute *attr, const char *buf, size_t count)
 {
-	int rc = -ENXIO;
+	int rc;
 	struct lcd_device *ld = to_lcd_device(dev);
 	unsigned long power;
 
@@ -116,6 +116,8 @@ static ssize_t lcd_store_power(struct device *dev,
 	if (rc)
 		return rc;
 
+	rc = -ENXIO;
+
 	mutex_lock(&ld->ops_lock);
 	if (ld->ops && ld->ops->set_power) {
 		pr_debug("set power to %lu\n", power);
@@ -144,7 +146,7 @@ static ssize_t lcd_show_contrast(struct device *dev,
 static ssize_t lcd_store_contrast(struct device *dev,
 		struct device_attribute *attr, const char *buf, size_t count)
 {
-	int rc = -ENXIO;
+	int rc;
 	struct lcd_device *ld = to_lcd_device(dev);
 	unsigned long contrast;
 
@@ -152,6 +154,8 @@ static ssize_t lcd_store_contrast(struct device *dev,
 	if (rc)
 		return rc;
 
+	rc = -ENXIO;
+
 	mutex_lock(&ld->ops_lock);
 	if (ld->ops && ld->ops->set_contrast) {
 		pr_debug("set contrast to %lu\n", contrast);