USB: gadget: f_hid: Fix memory leak in hidg_bind error path

commit 62783c3 upstream.

In hidg_bind(), if alloc_workqueue() fails after usb_assign_descriptors()
has successfully allocated the USB descriptors, the current error handling
does not call usb_free_all_descriptors() to free the allocated descriptors,
resulting in a memory leak.

Restructure the error handling by adding proper cleanup labels:
- fail_free_all: cleans up workqueue and descriptors
- fail_free_descs: cleans up descriptors only
- fail: original cleanup for earlier failures

This ensures that allocated resources are properly freed in reverse order
of their allocation, preventing the memory leak when alloc_workqueue() fails.

Fixes: a139c98 ("USB: gadget: f_hid: Add GET_REPORT via userspace IOCTL")
Cc: stable@vger.kernel.org
Signed-off-by: Yuhao Jiang <danisjiang@gmail.com>
Link: https://lore.kernel.org/r/20250623094844.244977-1-danisjiang@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: DanisJiang

drivers/usb/gadget/function/f_hid.c

@@ -1275,18 +1275,19 @@ static int hidg_bind(struct usb_configuration *c, struct usb_function *f)
 
 	if (!hidg->workqueue) {
 		status = -ENOMEM;
-		goto fail;
+		goto fail_free_descs;
 	}
 
 	/* create char device */
 	cdev_init(&hidg->cdev, &f_hidg_fops);
 	status = cdev_device_add(&hidg->cdev, &hidg->dev);
 	if (status)
-		goto fail_free_descs;
+		goto fail_free_all;
 
 	return 0;
-fail_free_descs:
+fail_free_all:
 	destroy_workqueue(hidg->workqueue);
+fail_free_descs:
 	usb_free_all_descriptors(f);
 fail:
 	ERROR(f->config->cdev, "hidg_bind FAILED\n");