issue 137 - correct computation of G

G was wrongly computed in some places, not taking into account
CQI and RI bits. This commit saves the correct value computed
in ulsch_decoding so we can reuse it in ulsch_decoding_data
(and the like).

Only the file openair1/PHY/LTE_TRANSPORT/ulsch_decoding.c has
been checked. If the computation is done somewhere else the
problem might still exist.