media: rc: mceusb: IR of length 0 means IR timeout, not reset

The last usb packet with IR data will end with 0x80 (MCE_IRDATA_TRAILER).
If we reset the decoder state at this point, IR decoding can fail.

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