qcacld-3.0: Fix memory leak in p2p oper chan change confirm action frame

In lim_oper_chan_change_confirm_tx_complete_cnf, need free frame buf
alloced in lim_p2p_oper_chan_change_confirm_action_frame, or buffer is
leaked.

Change-Id: Ic479427282742fb4fbbe28ab1acdf91e0a511340
CRs-Fixed: 2238603

core/mac/src/pe/lim/lim_send_management_frames.c

@@ -3739,6 +3739,8 @@ static QDF_STATUS lim_oper_chan_change_confirm_tx_complete_cnf(
 			void *params)
 {
 	pe_debug("tx_complete: %d", tx_complete);
+	if (buf)
+		qdf_nbuf_free(buf);
 	return QDF_STATUS_SUCCESS;
 }