Fix cleanup of NetEvWait class.

The destructor needs to delete the stored NetEvent objects. Failure
to do this was causing a compiler crash after synthesis if the
nodangle functor was disabled.

net_event.cc

@@ -369,6 +369,7 @@ NetEvWait::~NetEvWait()
 			tmp->next = tmp->next->next;
 			delete tmp;
 		  }
+		  delete tgt;
 	    }
 	    events_.clear();
       }