video_register_device() returns -EFOO on errr, not -1.

Addresses http://bugzilla.kernel.org/show_bug.cgi?id=9699

Reported-By: <devzero@web.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>