The harq_pid is set to inactive during the scheduling
of ACK/NACK, but this is happening before tx_req (PDSCH)
is recevied. We update the global harq_pid then use it
once we get the PDSCH PDU, then we set it to inactive.
Also, the global previously wasnt being set properly because
a memset was changing the def_dci_re15 struct. We now
memset after we update the harq_pid global.