qcacld-3.0: Flush packets in datapath error case

Several packets are sent to firmware in htt_htc_attach_all(), back to
back. However, if one of the latter packets fails to send for some
reason, the previous packets are not flushed. This leads to a number of
leaks under error conditions.

If a packet fails to send in htt_htc_attach_all(), flush the endpoint
before returning failure to the upper layers.

Change-Id: If9b33a645f7bcc77442e18566525ae57b544f1a0
CRs-Fixed: 2219137

core/dp/htt/htt.c

@@ -338,12 +338,20 @@ static int
 htt_htc_attach_all(struct htt_pdev_t *pdev)
 {
 	if (htt_htc_attach(pdev, HTT_DATA_MSG_SVC))
-		return -EIO;
+		goto flush_endpoint;
+
 	if (htt_htc_attach(pdev, HTT_DATA2_MSG_SVC))
-		return -EIO;
+		goto flush_endpoint;
+
 	if (htt_htc_attach(pdev, HTT_DATA3_MSG_SVC))
-		return -EIO;
+		goto flush_endpoint;
+
 	return 0;
+
+flush_endpoint:
+	htc_flush_endpoint(pdev->htc_pdev, ENDPOINT_0, HTC_TX_PACKET_TAG_ALL);
+
+	return -EIO;
 }
 #else
 /**