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

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

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: a139c98f760ef ("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>