[bug report] thermal/debugfs: Add thermal cooling device debugfs information

[Dan Carpenter <dan.carpenter@linaro.org>]

Hello Daniel Lezcano,

The patch 90f2fb4afe8b: "thermal/debugfs: Add thermal cooling device
debugfs information" from Jan 9, 2024 (linux-next), leads to the
following Smatch static checker warning:

drivers/thermal/thermal_debugfs.c:517 thermal_debug_cdev_remove() warn: 'thermal_dbg' was already freed. (line 515)
drivers/thermal/thermal_debugfs.c:835 thermal_debug_tz_remove() warn: 'thermal_dbg' was already freed. (line 833)

drivers/thermal/thermal_debugfs.c
    504 void thermal_debug_cdev_remove(struct thermal_cooling_device *cdev)
    505 {
    506         struct thermal_debugfs *thermal_dbg = cdev->debugfs;
    507 
    508         if (!thermal_dbg)
    509                 return;
    510 
    511         mutex_lock(&thermal_dbg->lock);
    512 
    513         thermal_debugfs_cdev_clear(&thermal_dbg->cdev_dbg);
    514         cdev->debugfs = NULL;
    515         thermal_debugfs_remove_id(thermal_dbg);
                                          ^^^^^^^^^^^
Freed here.

    516 
--> 517         mutex_unlock(&thermal_dbg->lock);
                             ^^^^^^^^^^^^^^^^^^
Use after free.  Same issue in the tz remove() function.

    518 }

regards,
dan carpenter