remove assertion in udcm

This commit was SVN r26790.

ompi/mca/btl/openib/connect/btl_openib_connect_udcm.c

@@ -1847,7 +1847,9 @@ static void *udcm_cq_event_dispatch(int fd, int flags, void *context)
     void *event_context;
     int rc;
 
-    assert (NULL != m && NULL != m->cm_channel);
+    if (OPAL_UNLIKELY(NULL == m || NULL == m->cm_channel)) {
+	return NULL;
+    }
 
     rc = ibv_get_cq_event (m->cm_channel, &event_cq, &event_context);