fixed the crash of LoadProhibited caused by taht

the nodes are deleted during the traversal of the linked list

components/bt/host/bluedroid/stack/btm/btm_acl.c

@@ -509,12 +509,14 @@ void btm_acl_device_down (void)
 {
     tACL_CONN   *p = NULL;
     BTM_TRACE_DEBUG ("btm_acl_device_down\n");
-    for (list_node_t *p_node = list_begin(btm_cb.p_acl_db_list); p_node; p_node = list_next(p_node)) {
-       p = list_node(p_node);
-       if (p && p->in_use) {
-           BTM_TRACE_DEBUG ("hci_handle=%d HCI_ERR_HW_FAILURE \n", p->hci_handle );
-           l2c_link_hci_disc_comp (p->hci_handle, HCI_ERR_HW_FAILURE);
-       }
+    for (list_node_t *p_node = list_begin(btm_cb.p_acl_db_list); p_node;) {
+        list_node_t *p_next = list_next(p_node);
+        p = list_node(p_node);
+        if (p && p->in_use) {
+            BTM_TRACE_DEBUG ("hci_handle=%d HCI_ERR_HW_FAILURE \n", p->hci_handle );
+            l2c_link_hci_disc_comp (p->hci_handle, HCI_ERR_HW_FAILURE);
+        }
+        p_node = p_next;
    }
 }
 /*******************************************************************************