poll: Count failed procedures

When a timeout has occured several times, the procedures handled by
poll_timeout are aborted. This happens when the number of repetitions
exceed N3105. Currently only the timeouts themselves are counted.

This commits adds counters that are incremented if a procedure has
really failed.

New counter:
- rlc.ass.failed:   Count failing UL and DL assigments via PACCH
- rlc.ack.failed:   Count failing DL Ack/Nack requests

Sponsored-by: On-Waves ehf
3 files changed