The d array has to be cleared at the first usage, which may not necessarily
be when new_rx is true. For example, in case of DTX detected for a first
transmission, the next transmission won't have new_rx true, so d won't be
cleared, containing data from a previous transmission. Or when a LDPC
decoding is cancelled for a segment when new_rx is true, a decoding for
a retransmission will not clear d because then new_rx will not be true.
(Yes, the logic of cancellation will be changed in the future, but the
changes will be orthogonal to the ones of this commit.)

new_rx is removed.