ret is set to 0 which do not indicate an error.
Return -EINVAL instead.

Fixes: a9e9dd9c ("hwmon: (ina3221) Read channel input source info from DT")
Signed-off-by: Marcus Folkesson <marcus.folkesson@gmail.com>
Link: https://lore.kernel.org/r/20230310075035.246083-1-marcus.folkesson@gmail.comSigned-off-by: Guenter Roeck <linux@roeck-us.net>