HBASE-15171 Avoid counting duplicate kv and generating lots of small hfiles in PutSortReducer (Yu Li)

hbase-server/src/main/java/org/apache/hadoop/hbase/mapreduce/PutSortReducer.java

@@ -67,9 +67,11 @@ public class PutSortReducer extends
           for (Cell cell: cells) {
             KeyValue kv = KeyValueUtil.ensureKeyValueTypeForMR(cell);
             map.add(kv);
-            curSize += kv.heapSize();
           }
         }
+        for(KeyValue kv: map){
+          curSize +=kv.heapSize();
+        }
       }
       context.setStatus("Read " + map.size() + " entries of " + map.getClass()
           + "(" + StringUtils.humanReadableInt(curSize) + ")");