First pass through action_list must happen early

The actions on the list may deal with what is then freed:

```
28: /home/travis/build/apache/qpid-dispatch/src/router_core/route_tables.c:530:17: runtime error: member access within null pointer of type 'struct qdr_node_t'
28:     #0 0x3ff9628d5bd in qdr_set_cost_CT /home/travis/build/apache/qpid-dispatch/src/router_core/route_tables.c:530
28:     #1 0x3ff9627e7cb in qdr_core_free /home/travis/build/apache/qpid-dispatch/src/router_core/router_core.c:251
28:     #2 0x3ff962e13f9 in qd_router_free /home/travis/build/apache/qpid-dispatch/src/router_node.c:2160
28:     #3 0x3ff9617979d in qd_dispatch_free /home/travis/build/apache/qpid-dispatch/src/dispatch.c:375
28:     #4 0x3ff9617979d in qd_dispatch_free /home/travis/build/apache/qpid-dispatch/src/dispatch.c:363
28:     #5 0x2aa23604fa9 in main_process /home/travis/build/apache/qpid-dispatch/router/src/main.c:119
28:     #6 0x2aa23604a23 in main /home/travis/build/apache/qpid-dispatch/router/src/main.c:369
28:     #7 0x3ff94faa5f9 in __libc_start_main (/lib/s390x-linux-gnu/libc.so.6+0x2a5f9)
28:     #8 0x2aa23604d23  (/home/travis/build/apache/qpid-dispatch/build/router/qdrouterd+0x4d23)
```

Author: jiridanek

src/router_core/router_core.c

@@ -131,6 +131,19 @@ qdr_core_t *qdr_core(qd_dispatch_t *qd, qd_router_mode_t mode, const char *area,
     return core;
 }
 
+static void discard_left_over_actions(qdr_core_t *core)
+{
+    qdr_action_list_t  action_list;
+    DEQ_MOVE(core->action_list, action_list);
+    DEQ_APPEND(action_list, core->action_list_background);
+    qdr_action_t *action = DEQ_HEAD(action_list);
+    while (action) {
+        DEQ_REMOVE_HEAD(action_list);
+        action->action_handler(core, action, true);
+        free_qdr_action_t(action);
+        action = DEQ_HEAD(action_list);
+    }
+}
 
 void qdr_core_free(qdr_core_t *core)
 {
@@ -152,6 +165,14 @@ void qdr_core_free(qdr_core_t *core)
     core->router_id = 0;
     core->router_area = 0;
 
+    //
+    // discard any left over actions
+    //
+
+    discard_left_over_actions(core);
+    // Drain the general work lists
+    qdr_general_handler(core);
+
     //
     // Free the core resources
     //
@@ -240,19 +261,11 @@ void qdr_core_free(qdr_core_t *core)
     // this must happen after qdrc_endpoint_do_cleanup_CT calls
     qdr_modules_finalize(core);
 
-    // discard any left over actions
-
-    qdr_action_list_t  action_list;
-    DEQ_MOVE(core->action_list, action_list);
-    DEQ_APPEND(action_list, core->action_list_background);
-    qdr_action_t *action = DEQ_HEAD(action_list);
-    while (action) {
-        DEQ_REMOVE_HEAD(action_list);
-        action->action_handler(core, action, true);
-        free_qdr_action_t(action);
-        action = DEQ_HEAD(action_list);
-    }
+    //
+    // discard any left over actions (again)
+    //
 
+    discard_left_over_actions(core);
     // Drain the general work lists
     qdr_general_handler(core);