Fixed the wave module testing on big-endian platforms.

array.fromfile() works only with file objects, not io.FileIO instances.

Lib/test/audiotests.py

@@ -6,7 +6,7 @@ import pickle
 import sys
 import base64
 
-class UnseekableIO(io.FileIO):
+class UnseekableIO(file):
     def tell(self):
         raise io.UnsupportedOperation