HID: trivial devm conversion for special hid drivers

It is safe to use devres allocation within the hid subsystem:
- the devres release is called _after_ the call to .remove(), meaning
  that no freed pointers will exists while removing the device
- if a .probe() fails, devres releases all the allocated ressources
  before going to the next driver: there will not be ghost ressources
  attached to a hid device if several drivers are probed.

Given that, we can clean up a little some of the HID drivers. These ones
are trivial:
- there is only one kzalloc in the driver
- the .remove() callback contains only one kfree on top of hid_hw_stop()
- the error path in the probe is easy enough to be manually checked

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

drivers/hid/hid-apple.c

@@ -349,7 +349,7 @@ static int apple_probe(struct hid_device *hdev,
 	unsigned int connect_mask = HID_CONNECT_DEFAULT;
 	int ret;
 
-	asc = kzalloc(sizeof(*asc), GFP_KERNEL);
+	asc = devm_kzalloc(&hdev->dev, sizeof(*asc), GFP_KERNEL);
 	if (asc == NULL) {
 		hid_err(hdev, "can't alloc apple descriptor\n");
 		return -ENOMEM;
@@ -362,7 +362,7 @@ static int apple_probe(struct hid_device *hdev,
 	ret = hid_parse(hdev);
 	if (ret) {
 		hid_err(hdev, "parse failed\n");
-		goto err_free;
+		return ret;
 	}
 
 	if (quirks & APPLE_HIDDEV)
@@ -373,19 +373,10 @@ static int apple_probe(struct hid_device *hdev,
 	ret = hid_hw_start(hdev, connect_mask);
 	if (ret) {
 		hid_err(hdev, "hw start failed\n");
-		goto err_free;
+		return ret;
 	}
 
 	return 0;
-err_free:
-	kfree(asc);
-	return ret;
-}
-
-static void apple_remove(struct hid_device *hdev)
-{
-	hid_hw_stop(hdev);
-	kfree(hid_get_drvdata(hdev));
 }
 
 static const struct hid_device_id apple_devices[] = {
@@ -545,7 +536,6 @@ static struct hid_driver apple_driver = {
 	.id_table = apple_devices,
 	.report_fixup = apple_report_fixup,
 	.probe = apple_probe,
-	.remove = apple_remove,
 	.event = apple_event,
 	.input_mapping = apple_input_mapping,
 	.input_mapped = apple_input_mapped,