bpo-28315: Improve code examples in docs (GH-1372)

Replace
   File "<stdin>", line 1, in ? 
with 
   File "<stdin>", line 1, in <module>
diff --git a/Doc/library/fpectl.rst b/Doc/library/fpectl.rst
index e4b528c..9660716 100644
--- a/Doc/library/fpectl.rst
+++ b/Doc/library/fpectl.rst
@@ -89,7 +89,7 @@
    >>> import math
    >>> math.exp(1000)
    Traceback (most recent call last):
-     File "<stdin>", line 1, in ?
+     File "<stdin>", line 1, in <module>
    FloatingPointError: in math_1