Input: lm8323 - missing error check in lm8323_set_disable()

The missing error handling here is not especially harmful but static
checkers complain that "i" can be used uninitialized.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

drivers/input/keyboard/lm8323.c

@@ -616,6 +616,8 @@ static ssize_t lm8323_set_disable(struct device *dev,
 	unsigned int i;
 
 	ret = kstrtouint(buf, 10, &i);
+	if (ret)
+		return ret;
 
 	mutex_lock(&lm->lock);
 	lm->kp_enabled = !i;