qcacld-3.0: Memzero htt_frag_desc before use

Presently, htt_frag_desc is not getting zeroed out explicitly.
So fw can take the invalid/garbage data in the frag information
and treat it as a valid address which may lead to crash.

Memzero htt_frag_desc before use.

Change-Id: I9dadcb883a65c43f96e810a12b4fb491c3a2e734
CRs-Fixed: 2088448

core/dp/txrx/ol_tx.c

@@ -556,6 +556,7 @@ ol_tx_prepare_ll_fast(struct ol_txrx_pdev_t *pdev,
 	}
 
 	htt_tx_desc = tx_desc->htt_tx_desc;
+	qdf_mem_zero(tx_desc->htt_frag_desc, sizeof(struct msdu_ext_desc_t));
 
 	/* Make sure frags num is set to 0 */
 	/*