Correct a couple of unbalanced parenthesis. (GH-10779)

(cherry picked from commit 55f41e45b4318cbe19209f5144641344d0049fb8)

Co-authored-by: Andre Delfino <adelfino@gmail.com>
diff --git a/Doc/faq/extending.rst b/Doc/faq/extending.rst
index b611bb4..74e1af6 100644
--- a/Doc/faq/extending.rst
+++ b/Doc/faq/extending.rst
@@ -277,7 +277,7 @@
 thread as your rest application and you can't allow the
 :c:func:`PyRun_InteractiveLoop` to stop while waiting for user input.  The one
 solution then is to call :c:func:`PyParser_ParseString` and test for ``e.error``
-equal to ``E_EOF``, which means the input is incomplete).  Here's a sample code
+equal to ``E_EOF``, which means the input is incomplete.  Here's a sample code
 fragment, untested, inspired by code from Alex Farber::
 
    #include <Python.h>