fix argument error (#2965)

Summary:
the argument in IndexIVFPQ constructor should be pq.M, not code_size

Pull Request resolved: #2965

Reviewed By: algoriddle

Differential Revision: D48024513

Pulled By: mdouze

fbshipit-source-id: d5cb92a32bbcb647ee12a4bc6b026059c20740db

faiss/gpu/GpuCloner.cpp

@@ -333,7 +333,7 @@ Index* ToGpuClonerMultiple::clone_Index_to_shards(const Index* index) {
                     const_cast<Index*>(quantizer),
                     index_ivfpq->d,
                     index_ivfpq->nlist,
-                    index_ivfpq->code_size,
+                    index_ivfpq->pq.M,
                     index_ivfpq->pq.nbits);
             idx2.metric_type = index_ivfpq->metric_type;
             idx2.pq = index_ivfpq->pq;