[media] dib0700: Fix memory leak during initialization

Reported by kmemleak.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Mauro Carvalho Chehab <mchehab@infradead.org>
Cc: Devin Heitmueller <dheitmueller@kernellabs.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>