gh-113113: doc: use less ambiguously named variable (gh-113114)

Author: jeremy-dolan

Doc/tutorial/controlflow.rst

@@ -559,10 +559,10 @@ defined to allow.  For example::
 
    def ask_ok(prompt, retries=4, reminder='Please try again!'):
        while True:
-           ok = input(prompt)
-           if ok in ('y', 'ye', 'yes'):
+           reply = input(prompt)
+           if reply in {'y', 'ye', 'yes'}:
                return True
-           if ok in ('n', 'no', 'nop', 'nope'):
+           if reply in {'n', 'no', 'nop', 'nope'}:
                return False
            retries = retries - 1
            if retries < 0: