[2.7] bpo-28315: Improve code examples in docs (GH-1372) (#1447)

Replace
   File "<stdin>", line 1, in ?
with
   File "<stdin>", line 1, in <module>.
(cherry picked from commit 8856940cf2e82cb17db2b684cd5732fe658605ca)
diff --git a/Doc/howto/functional.rst b/Doc/howto/functional.rst
index ee9a5f6d..a06e29c 100644
--- a/Doc/howto/functional.rst
+++ b/Doc/howto/functional.rst
@@ -207,7 +207,7 @@
     3
     >>> it.next()
     Traceback (most recent call last):
-      File "<stdin>", line 1, in ?
+      File "<stdin>", line 1, in <module>
     StopIteration
     >>>
 
@@ -477,7 +477,7 @@
     2
     >>> gen.next()
     Traceback (most recent call last):
-      File "stdin", line 1, in ?
+      File "stdin", line 1, in <module>
       File "stdin", line 2, in generate_ints
     StopIteration
 
@@ -581,7 +581,7 @@
     9
     >>> print it.next()
     Traceback (most recent call last):
-      File "t.py", line 15, in ?
+      File "t.py", line 15, in <module>
         print it.next()
     StopIteration