Fix slim log format, test=develop (#22281)

python/paddle/fluid/contrib/slim/core/compressor.py

@@ -220,7 +220,7 @@ class Context(object):
                         batch_id, eval_graph.out_nodes.keys(), result))
                 batch_id += 1
 
-        result = np.mean(np.array(results), axis=0)
+        result = list(np.mean(np.array(results), axis=0))
         _logger.info("Final eval result: {}={}".format(
             eval_graph.out_nodes.keys(), result))
         if not isinstance(result, Iterable):