thermal/core: Fix memory leak in the error path

Fix the following error:

smatch warnings:
drivers/thermal/thermal_core.c:1020 __thermal_cooling_device_register() warn: possible memory leak of 'cdev'

by freeing the cdev when exiting the function in the error path.

Fixes: 584837618100 ("thermal/drivers/core: Use a char pointer for the cooling device name")
Reported-by: kernel test robot <[e-mail]>
Reported-by: Dan Carpenter <[e-mail]>
Signed-off-by: Daniel Lezcano <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]

drivers/thermal/thermal_core.c

···
 out_ida_remove:
 	ida_simple_remove(&thermal_cdev_ida, cdev->id);
 out_kfree_cdev:
+	kfree(cdev);
 	return ERR_PTR(ret);
 }