Make sure to always cancel the control URB in write() so that it can be
reused after a timeout or spurious CMD_ACK.

Currently any further write requests after a timeout would fail after
triggering a WARN() in usb_submit_urb() when attempting to submit the
already active URB.

Reported-by:  <syzbot+e87ebe0f7913f71f2ea5@syzkaller.appspotmail.com>
Fixes: 6bc235a2 ("USB: add driver for Meywa-Denki & Kayac YUREX")
Cc: stable <stable@vger.kernel.org>     # 2.6.37
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>