hwmon: (sht3x) Fix error handling

[ Upstream commit 8dcc66ad ]

Handling of errors when reading status, temperature, and humidity returns
the error number as negative attribute value. Fix it up by returning
the error as return value.

Fixes: a0ac418c ("hwmon: (sht3x) convert some of sysfs interface to hwmon")
Cc: JuenKit Yip <JuenKit_Yip@hotmail.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>