V4L/DVB (13184): gspca: Don't forget to resubmit URB's in case of an error

The gscpa core was not resubmitting URB's when the URB status was an error,
this means we will loose URB's (potentially all stopping the stream) in
case of sporadic USB issues. I've seen this with an Aiptek stv0680 based
PenCam connected through an USB 2.0 hub.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>