media: digitv: don't continue if remote control state can't be read

This results in an uninitialized variable read.

Reported-by:  <syzbot+6bf9606ee955b646c0e1@syzkaller.appspotmail.com>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>