Inline the variable and avoid potential resource leak warning

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/fileupload/trunk@1568863 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/src/main/java/org/apache/commons/fileupload/MultipartStream.java b/src/main/java/org/apache/commons/fileupload/MultipartStream.java
index 3438342..bf460f4 100644
--- a/src/main/java/org/apache/commons/fileupload/MultipartStream.java
+++ b/src/main/java/org/apache/commons/fileupload/MultipartStream.java
@@ -589,8 +589,7 @@
      */
     public int readBodyData(OutputStream output)
             throws MalformedStreamException, IOException {
-        final InputStream istream = newInputStream();
-        return (int) Streams.copy(istream, output, false); // N.B. Streams.copy closes the input stream
+        return (int) Streams.copy(newInputStream(), output, false); // N.B. Streams.copy closes the input stream
     }
 
     /**