Fix test on Linux

Author: aisk

Lib/test/test_concurrent_futures/test_interpreter_pool.py

@@ -509,9 +509,10 @@ def f():
             import _thread
             return _thread._get_name()
 
+        # Some platforms (Linux) are using 16 bytes to store the thread name,
+        # so only compare the first 15 bytes (without the trailing \n).
         self.assertStartsWith(self.executor.submit(f).result(),
-                              "InterpreterPoolExecutor-")
-
+                              "InterpreterPoolExecutor-"[:15])
 
 class AsyncioTest(InterpretersMixin, testasyncio_utils.TestCase):