[media] gspca/stv06xx_pb0100: Don't potentially deref NULL in pb0100_start()
[media] gspca/stv06xx_pb0100: Don't potentially deref NULL in pb0100_start()

usb_altnum_to_altsetting() may return NULL. If it does we'll dereference a
NULL pointer in
drivers/media/video/gspca/stv06xx/stv06xx_pb0100.c::pb0100_start().
As far as I can tell there's not really anything more sensible than
-ENODEV that we can return in that situation, but I'm not at all intimate
with this code so I'd like a bit of review/comments on this before it's
applied.
Anyway, here's a proposed patch.

Signed-off-by: Jesper Juhl <7323a5431d1c31072983a6a5bf23745b655ddf59@chaosbits.net>
Cc: Jean-Francois Moine <e5394ce9c4b9ae7d2c4686830c5ac5f3b9028b6a@free.fr>
Cc: Hans de Goede <9fa1be1a5b5729e4c6b404f34c9ce49ff4882fd8@redhat.com>
Cc: Erik Andren <1e681b7888245a64a1352e28c19b66ddbad14d09@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <ad86ba2154032c9f55743a190faa2459a9d61d42@redhat.com>

KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs