rlc: Use the rlc structure to access the data unit in the RLC message

Currently most offsets are hard-coded which makes it difficult to
access the data units and their headers when padding has to be taken
into account. These offset are already provided by the
gprs_rlc_data_info_init_ul/dl functions.

Change the encoder/decoder to use these values.

Note that some assumptions (bit alignment) are still present in the
code and checked by assertions.

Sponsored-by: On-Waves ehf
2 files changed