pcu: TC_mo_ping_pong: Check DL block is sent and ACK it

Function f_rx_rlcmac_dl_block_exp_data() still misses proper
verification of data. Apparently the received message has 2 blocks,
first with expected 10 bytes, but next one contains 18 bytes with 4
actual bytes and other bits are padding.

Last DL ACK/NACK sent is not yet working correctly. osmo-pcu seems to be
unable to match it against sent DL block (I think due to non-matching
FN), and instead drops it and schedules after timeout an IMM ASS to try
to send DL block again.

Change-Id: Icf66dd5c07690368722c586632c38fb7e770053c
3 files changed