qcacmn: Handle the duplicate entries in reo exception ring

We have come across scenarios where rxdma is pushing
a certain entry more than once to the reo exception
ring. In this scenario, when we try to unmap a buffer,
it can lead to multiple unmap of the same buffer.

Handle this case, by skipping the process of this
duplicate entry, if alrady unmapped, and proceed to the
next entry.

Change-Id: Iae66f27e432f795ba4730911029fa1d63a75cb06
CRs-Fixed: 2739176

dp/wifi3.0/dp_rx_defrag.c

@@ -1905,6 +1905,10 @@ uint32_t dp_rx_frag_handle(struct dp_soc *soc, hal_ring_desc_t ring_desc,
 	msdu = rx_desc->nbuf;
 
 	rx_desc_pool = &soc->rx_desc_buf[rx_desc->pool_id];
+
+	if (rx_desc->unmapped)
+		return rx_bufs_used;
+
 	dp_ipa_handle_rx_buf_smmu_mapping(soc, rx_desc->nbuf,
 					  rx_desc_pool->buf_size,
 					  false);