staging: rtl8712: fix a potential memory leak in r871xu_drv_init()

staging: rtl8712: fix a potential memory leak in r871xu_drv_init()

In r871xu_drv_init(), if r8712_init_drv_sw() fails, then the memory
allocated by r8712_alloc_io_queue() in r8712_usb_dvobj_init() is not
properly released as there is no action will be performed by
r8712_usb_dvobj_deinit().
To properly release it, we should call r8712_free_io_queue() in
r8712_usb_dvobj_deinit().

Besides, in r871xu_dev_remove(), r8712_usb_dvobj_deinit() will be called
by r871x_dev_unload() under condition `padapter->bup` and
r8712_free_io_queue() is called by r8712_free_drv_sw().
However, r8712_usb_dvobj_deinit() does not rely on `padapter->bup` and
calling r8712_free_io_queue() in r8712_free_drv_sw() is negative for
better understading the code.
So I move r8712_usb_dvobj_deinit() into r871xu_dev_remove(), and remove
r8712_free_io_queue() from r8712_free_drv_sw().

Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Xiaoke Wang <xkernel.wang@foxmail.com>
Link: https://lore.kernel.org/r/tencent_B8048C592777830380A23A7C4409F9DF1305@qq.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>