media: ati_remote: sanity check for both endpoints

If you do sanity checks, you should do them for both endpoints.
Hence introduce checking for endpoint type for the output
endpoint, too.

Reported-by:  <syzbot+998261c2ae5932458f6c@syzkaller.appspotmail.com>
Signed-off-by: Oliver Neukum <oneukum@suse.com>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>