regulator: fp9931: Fix PM runtime reference leak in fp9931_hwmon_read()

In the Linux kernel, the following vulnerability has been resolved: regulator: fp9931: Fix PM runtime reference leak in fp9931_hwmon_read() In fp9931_hwmon_read(), if regmap_read() failed, the function returned the error code without calling pm_runtime_put_autosuspend(), causing a PM reference leak.