edge: Compare len instead of using cs.isCombinable

Comparing the coding scheme properties doesn't seem to be strong
enough, since create_dl_acked_block(fn, ts, index, index2) sometimes
had to combine data units of different size this way.

Check the registered size of the BSN blocks instead, since these must
match if two blocks are to be combined in a single RLC data message
with MCS7-9.

It is not yet clear, what exactly goes wrong with the current
implementation, but this commit fixes the problem which trigger the
assertion in create_dl_acked_block.

Sponsored-by: On-Waves ehf
2 files changed