hwmon: (emc2103) fix unable to change fan pwm1_enable attribute

BugLink: https://bugs.launchpad.net/bugs/1888690

commit 14b0e83d upstream.

This patch fixes a bug which does not let FAN mode to be changed from
sysfs(pwm1_enable). i.e pwm1_enable can not be set to 3, it will always
remain at 0.

This is caused because the device driver handles the result of
"read_u8_from_i2c(client, REG_FAN_CONF1, &conf_reg)" incorrectly. The
driver thinks an error has occurred if the (result != 0). This has been
fixed by changing the condition to (result < 0).
Signed-off-by: Vishwas M <vishwas.reddy.vr@gmail.com>
Link: https://lore.kernel.org/r/20200707142747.118414-1-vishwas.reddy.vr@gmail.com
Fixes: 9df7305b ("hwmon: Add driver for SMSC EMC2103 temperature monitor and fan controller")
Cc: stable@vger.kernel.org
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>

drivers/hwmon/emc2103.c

@@ -452,7 +452,7 @@ static ssize_t set_pwm_enable(struct device *dev, struct device_attribute *da,
 	}
 
 	result = read_u8_from_i2c(client, REG_FAN_CONF1, &conf_reg);
-	if (result) {
+	if (result < 0) {
 		count = result;
 		goto err;
 	}