thermal/lib: Fix memory leak on error in thermal_genl_auto()

thermal/lib: Fix memory leak on error in thermal_genl_auto()

The function thermal_genl_auto() does not free the allocated message
in the error path. Fix that by putting a out label and jump to it
which will free the message instead of directly returning an error.

Fixes: 47c4b0de080a ("tools/lib/thermal: Add a thermal library")
Reported-by: Lukasz Luba <lukasz.luba@arm.com>\a
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Link: https://patch.msgid.link/20241024105938.1095358-1-daniel.lezcano@linaro.org
[ rjw: Fixed up the !msg error path, added Fixes tag ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>