[Embedding] Fix embedding_lookup_sparse construct graph issue. (#176)

Author: liutongxuan

tensorflow/python/ops/embedding_ops.py

@@ -589,11 +589,11 @@ def embedding_lookup_sparse(params,
       segment_ids = math_ops.cast(segment_ids, dtypes.int32)
 
     ids = sp_ids.values
-    if isinstance(params[0], kv_variable_ops.EmbeddingVariable) and params[0]._filter_freq == 0:
+    if isinstance(params[0], kv_variable_ops.EmbeddingVariable) and params[0]._filter_freq > 0:
+      ids, idx, counts = array_ops.unique_with_counts(ids)
+    else:
       ids, idx = array_ops.unique(ids)
       counts = None
-    else:
-      ids, idx, counts = array_ops.unique_with_counts(ids)
 
     uniqued_blocknums = None
     if blocknums is not None: