leds: lp5521: Fix return value

Return the value obtained from i2c_smbus_read_byte_data() instead of
-EIO. Silences the following smatch warning:
drivers/leds/leds-lp5521.c:155 lp5521_read() info:
why not propagate 'ret' from i2c_smbus_read_byte_data() instead of -5?

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Bryan Wu <cooloney@gmail.com>
diff --git a/drivers/leds/leds-lp5521.c b/drivers/leds/leds-lp5521.c
index 362e29e..8505afe 100644
--- a/drivers/leds/leds-lp5521.c
+++ b/drivers/leds/leds-lp5521.c
@@ -152,7 +152,7 @@
 
 	ret = i2c_smbus_read_byte_data(client, reg);
 	if (ret < 0)
-		return -EIO;
+		return ret;
 
 	*buf = ret;
 	return 0;