[media] gspca: Check dev->actconfig rather than dev->config

Check dev->actconfig rather than dev->config when checking various
configuration things. dev->config points to the array of configs for the
device so dev->config->foo boils down to dev->config[0].foo and the first
config is not necessarily always the active config.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Jean-François Moine <moinejf@free.fr>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>