qcacmn: Check if ast hash table is populated before accessing

Check if ast hash table is populated before accessing it,
as some calls from ecm can try to access the hash table when it
is down

Change-Id: I6d38359c3cf13f578671794db61c8eb845245d6d
CRs-Fixed: 3186437

dp/wifi3.0/dp_peer.c

@@ -1404,6 +1404,9 @@ struct dp_ast_entry *dp_peer_ast_hash_find_soc(struct dp_soc *soc,
 	unsigned index;
 	struct dp_ast_entry *ase;
 
+	if (!soc->ast_hash.bins)
+		return NULL;
+
 	qdf_mem_copy(&local_mac_addr_aligned.raw[0],
 			ast_mac_addr, QDF_MAC_ADDR_SIZE);
 	mac_addr = &local_mac_addr_aligned;