qcacmn: Fix a coding error of ill use of qdf_mem_set()

There is an ill use of qdf_mem_set() in dp_htt_t2h_msg_handler().
This change fixes this issue by assigning 0 to the local struct
variable instead of the memset, which can also reduce some code.

Change-Id: I303c1adc167a8e1ab82692a294fe28bc4e8a97dc
CRs-Fixed: 3443572

dp/wifi3.0/dp_htt.c

@@ -3824,10 +3824,7 @@ void dp_htt_t2h_msg_handler(void *context, HTC_PACKET *pkt)
 			u_int8_t vdev_id;
 			bool is_wds;
 			u_int16_t ast_hash;
-			struct dp_ast_flow_override_info ast_flow_info;
-
-			qdf_mem_set(&ast_flow_info, 0,
-					    sizeof(struct dp_ast_flow_override_info));
+			struct dp_ast_flow_override_info ast_flow_info = {0};
 
 			peer_id = HTT_RX_PEER_MAP_V2_SW_PEER_ID_GET(*msg_word);
 			hw_peer_id =