usb: usbfs: fix double-free of usb memory upon submiturb error

usb: usbfs: fix double-free of usb memory upon submiturb error

commit c43f28dfdc4654e738aa6d3fd08a105b2bee758d upstream.

Upon an error within proc_do_submiturb(), dec_usb_memory_use_count()
gets called once by the error handling tail and again by free_async().
Remove the first call.

Signed-off-by: Gavin Li <git@thegavinli.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20190804235044.22327-1-gavinli@thegavinli.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>