dialog: access dialog table entry by reference for dmq_send_all_dlgs

- avoid race conditions to get and release the lock when entry structure
is copied in local variable
- GH #2570, GH #2547

src/modules/dialog/dlg_dmq.c

@@ -646,22 +646,22 @@ int dlg_dmq_replicate_action(dlg_dmq_action_t action, dlg_cell_t* dlg,
 
 int dmq_send_all_dlgs(dmq_node_t* dmq_node) {
 	int index;
-	dlg_entry_t entry;
+	dlg_entry_t *entry;
 	dlg_cell_t *dlg;
 
 	LM_DBG("sending all dialogs \n");
 
 	for(index = 0; index< d_table->size; index++){
 		/* lock the whole entry */
-		entry = (d_table->entries)[index];
-		dlg_lock( d_table, &entry);
+		entry = &d_table->entries[index];
+		dlg_lock( d_table, entry);
 
-		for(dlg = entry.first; dlg != NULL; dlg = dlg->next){
+		for(dlg = entry->first; dlg != NULL; dlg = dlg->next){
 			dlg->dflags |= DLG_FLAG_CHANGED_PROF;
 			dlg_dmq_replicate_action(DLG_DMQ_UPDATE, dlg, 0, dmq_node);
 		}
 
-		dlg_unlock( d_table, &entry);
+		dlg_unlock( d_table, entry);
 	}
 
 	return 0;