Fixed the wave module testing on big-endian platforms.

array.fromfile() works only with file objects, not io.FileIO instances.
diff --git a/Lib/test/audiotests.py b/Lib/test/audiotests.py
index 93576e6..f4abd2a 100644
--- a/Lib/test/audiotests.py
+++ b/Lib/test/audiotests.py
@@ -6,7 +6,7 @@
 import sys
 import base64
 
-class UnseekableIO(io.FileIO):
+class UnseekableIO(file):
     def tell(self):
         raise io.UnsupportedOperation