hwmon: (ina238) Correctly clamp temperature

hwmon: (ina238) Correctly clamp temperature

ina238_write_temp() was attempting to clamp the user input but was
throwing away the result. Ensure that we clamp the value to the
appropriate range before it is converted into a register value.

Fixes: 0d9f596b1fe3 ("hwmon: (ina238) Modify the calculation formula to adapt to different chips")
Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Link: https://lore.kernel.org/r/20250829030512.1179998-3-chris.packham@alliedtelesis.co.nz
Signed-off-by: Guenter Roeck <linux@roeck-us.net>