thermal: hwmon: Fix critical temperature attribute removal

thermal: hwmon: Fix critical temperature attribute removal

Since the return value of thermal_zone_crit_temp_valid() depends on
the behavior of the thermal zone .get_crit_temp() callback which
may change over time in theory, thermal_remove_hwmon_sysfs() may
attempt to remove a critical temperature attribute that has not
been created, passing a pointer to an uninitialized attribute
structure to device_remove_file().

To avoid that, set a flag in struct thermal_hwmon_temp after creating
a critical temperature attribute and use the value of that flag to
decide whether or not the attribute needs to be removed.

Fixes: e8db5d6736a7 ("thermal: hwmon: Make the check for critical temp valid consistent")
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://patch.msgid.link/2437056.ElGaqSPkdT@rafael.j.wysocki
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>