media: rc: mce_kbd decoder: remove superfluous call to input_sync

There is nothing to sync in this code path.

Reported-by: Matthias Reichl <hias@horus.com>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>