USB: mos7840: remove NULL-urb submission

commit 28c3ae9a8cf45f439c9a0779ebd0256e2ae72813 upstream.

The private int_urb is never allocated so the submission from the
control completion handler will always fail. Remove this odd piece of
broken code.

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>