qcacld-3.0: Update htc_endpoint only for htt tx endpoint
Update htc_endpoint only for htt tx endpoint to avoid
double freeing of Tx Queue packets as it will be
freed in htt_htc_misc_pkt_pool_free.
Rename htc_endpoint to htc_htt_tx_endpoint to reflect
it's appropriate use.
Change-Id: I736ba08505acc829eb15be30538553dd945695f6
CRs-Fixed: 1006498