leds: leds-lp5523: fix build warnings

This patch fixes build warnings as below:

drivers/leds/leds-lp5523.c: In function 'lp5523_selftest':
drivers/leds/leds-lp5523.c:496:18: warning: 'adc' may be used uninitialized in this function [-Wuninitialized]
drivers/leds/leds-lp5523.c:471:5: warning: 'vdd' may be used uninitialized in this function [-Wuninitialized]
drivers/leds/leds-lp5523.c: In function 'lp5523_probe':
drivers/leds/leds-lp5523.c:252:9: warning: 'status' may be used uninitialized in this function [-Wuninitialized]
drivers/leds/leds-lp5523.c:201:5: note: 'status' was declared here

If lp5523_read() returns an error, problems will happen. Thus,
when lp5523_read() returns an error, it should be handled.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Bryan Wu <cooloney@gmail.com>

drivers/leds/leds-lp5523.c

@@ -248,7 +248,10 @@ static int lp5523_configure(struct i2c_client *client)
 
 	/* Let the programs run for couple of ms and check the engine status */
 	usleep_range(3000, 6000);
-	lp5523_read(client, LP5523_REG_STATUS, &status);
+	ret = lp5523_read(client, LP5523_REG_STATUS, &status);
+	if (ret < 0)
+		return ret;
+
 	status &= LP5523_ENG_STATUS_MASK;
 
 	if (status == LP5523_ENG_STATUS_MASK) {
@@ -464,10 +467,16 @@ static ssize_t lp5523_selftest(struct device *dev,
 				    LP5523_EN_LEDTEST | 16);
 	usleep_range(3000, 6000); /* ADC conversion time is typically 2.7 ms */
 	ret = lp5523_read(chip->client, LP5523_REG_STATUS, &status);
+	if (ret < 0)
+		goto fail;
+
 	if (!(status & LP5523_LEDTEST_DONE))
 		usleep_range(3000, 6000); /* Was not ready. Wait little bit */
 
-	ret |= lp5523_read(chip->client, LP5523_REG_LED_TEST_ADC, &vdd);
+	ret = lp5523_read(chip->client, LP5523_REG_LED_TEST_ADC, &vdd);
+	if (ret < 0)
+		goto fail;
+
 	vdd--;	/* There may be some fluctuation in measurement */
 
 	for (i = 0; i < LP5523_LEDS; i++) {
@@ -489,9 +498,14 @@ static ssize_t lp5523_selftest(struct device *dev,
 		/* ADC conversion time is 2.7 ms typically */
 		usleep_range(3000, 6000);
 		ret = lp5523_read(chip->client, LP5523_REG_STATUS, &status);
+		if (ret < 0)
+			goto fail;
+
 		if (!(status & LP5523_LEDTEST_DONE))
 			usleep_range(3000, 6000);/* Was not ready. Wait. */
-		ret |= lp5523_read(chip->client, LP5523_REG_LED_TEST_ADC, &adc);
+		ret = lp5523_read(chip->client, LP5523_REG_LED_TEST_ADC, &adc);
+		if (ret < 0)
+			goto fail;
 
 		if (adc >= vdd || adc < LP5523_ADC_SHORTCIRC_LIM)
 			pos += sprintf(buf + pos, "LED %d FAIL\n", i);