Staging: android: timed_gpio: Properly discard invalid timeout values.

The timed output device never previously checked the return value of sscanf,
resulting in an uninitialized int being passed to enable() if input value
was invalid.

Signed-off-by: Mike Lockwood <lockwood@android.com>

drivers/staging/android/timed_output.c

@@ -41,7 +41,9 @@ static ssize_t enable_store(
 	struct timed_output_dev *tdev = dev_get_drvdata(dev);
 	int value;
 
-	sscanf(buf, "%d", &value);
+	if (sscanf(buf, "%d", &value) != 1)
+		return -EINVAL;
+
 	tdev->enable(tdev, value);
 
 	return size;