qcacmn: Fix multiple unmap of same netbuf

Clear HTC_TX_PACKET_FLAG_FIXUP_NETBUF flag in
hif_send_head failure scenario to avoid
multiple unamap of same netbuf.

Change-Id: Id7f6aeba1eff0d23b76927fcbb03643409fc7859
CRs-Fixed: 2437034
1 file changed