[media] ati_remote: fix check for a weird byte

The ati_remote_dump() function tries to not print "Weird byte" warning
for 1-byte responses that contain 0xff or 0x00, but it doesn't work
properly as it simply falls back to the "Weird data" warning in the else
clause.

Fix that by adding an inner if clause.

Signed-off-by: Anssi Hannula <anssi.hannula@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>