Free struct device in fw_dev_release()

The f_dev in _request_firmware() is allocated via the fw_setup_device()
and fw_register_device() calls and its class set to firmware_class (the
class release function is fw_dev_release).

Commit 6acf70f0 replaced the kfree(dev) in fw_dev_release() with a
put_device() call but my understanding is that the release function is
called via put_device -> kobject_put -> kref_put -> koject_release etc.
and it should call kfree since it's the last to see this device
structure alive.

Because of that, the _request_firmware() function on its -ENOENT error
path only calls device_unregister(f_dev) which would eventually call
fw_dev_release() but there is no kfree (the subsequent put_device call
would just make the kref negative).
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Acked-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Acked-by: NMing Lei <tom.leiming@gmail.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

drivers/base/firmware_class.c

@@ -357,7 +357,7 @@ static void fw_dev_release(struct device *dev)
 	kfree(fw_priv->pages);
 	kfree(fw_priv->fw_id);
 	kfree(fw_priv);
-	put_device(dev);
+	kfree(dev);
 
 	module_put(THIS_MODULE);
 }
@@ -408,13 +408,11 @@ static int fw_register_device(struct device **dev_p, const char *fw_name,
 	if (retval) {
 		dev_err(device, "%s: device_register failed\n", __func__);
 		put_device(f_dev);
-		goto error_kfree_fw_id;
+		return retval;
 	}
 	*dev_p = f_dev;
 	return 0;
 
-error_kfree_fw_id:
-	kfree(fw_priv->fw_id);
 error_kfree:
 	kfree(f_dev);
 	kfree(fw_priv);