[media] imon: don't wedge hardware after early callbacks

This patch is just a minor update to one titled "imon: Input from ffdc
device type ignored" from Corinna Vinschen. An earlier patch to prevent
an oops when we got early callbacks also has the nasty side-effect of
wedging imon hardware, as we don't acknowledge the urb. Rework the check
slightly here to bypass processing the packet, as the driver isn't yet
fully initialized, but still acknowlege the urb and submit a new rx_urb.
Do this for both interfaces -- irrelevant for ffdc hardware, but
relevant for newer hardware, though newer hardware doesn't spew the
constant stream of data as soon as the hardware is initialized like the
older ffdc devices, so they'd be less likely to trigger this anyway...

Tested with both an ffdc device and an 0042 device.

Reported-by: Corinna Vinschen <vinschen@redhat.com>
Signed-off-by: Jarod Wilson <jarod@redhat.com>
CC: stable@vger.kernel.org
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>