hwmon: (nct7802) Fix wrong detection of in4 presence

BugLink: https://bugs.launchpad.net/bugs/1845038

commit 38ada2f4 upstream.

The code to detect if in4 is present is wrong; if in4 is not present,
the in4_input sysfs attribute is still present.

In detail:

- Ihen RTD3_MD=11 (VSEN3 present), everything is as expected (no bug).
- If we have RTD3_MD!=11 (no VSEN3), we unexpectedly have a in4_input
  file under /sys and the "sensors" command displays in4_input.
  But as expected, we have no in4_min, in4_max, in4_alarm, in4_beep.

Fix is_visible function to detect and report in4_input visibility
as expected.
Reported-by: Gilles Buloz <Gilles.Buloz@kontron.com>
Cc: Gilles Buloz <Gilles.Buloz@kontron.com>
Cc: stable@vger.kernel.org
Fixes: 3434f378 ("hwmon: Driver for Nuvoton NCT7802Y")
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Connor Kuehl <connor.kuehl@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>

drivers/hwmon/nct7802.c

@@ -768,7 +768,7 @@ static struct attribute *nct7802_in_attrs[] = {
 	&sensor_dev_attr_in3_alarm.dev_attr.attr,
 	&sensor_dev_attr_in3_beep.dev_attr.attr,
 
-	&sensor_dev_attr_in4_input.dev_attr.attr,	/* 17 */
+	&sensor_dev_attr_in4_input.dev_attr.attr,	/* 16 */
 	&sensor_dev_attr_in4_min.dev_attr.attr,
 	&sensor_dev_attr_in4_max.dev_attr.attr,
 	&sensor_dev_attr_in4_alarm.dev_attr.attr,
@@ -794,9 +794,9 @@ static umode_t nct7802_in_is_visible(struct kobject *kobj,
 
 	if (index >= 6 && index < 11 && (reg & 0x03) != 0x03)	/* VSEN1 */
 		return 0;
-	if (index >= 11 && index < 17 && (reg & 0x0c) != 0x0c)	/* VSEN2 */
+	if (index >= 11 && index < 16 && (reg & 0x0c) != 0x0c)	/* VSEN2 */
 		return 0;
-	if (index >= 17 && (reg & 0x30) != 0x30)		/* VSEN3 */
+	if (index >= 16 && (reg & 0x30) != 0x30)		/* VSEN3 */
 		return 0;
 
 	return attr->mode;