Minor doc improvement (GH-10341)

Change "star-operator" to "* operator".
diff --git a/Doc/tutorial/controlflow.rst b/Doc/tutorial/controlflow.rst
index 9057345..abf163d 100644
--- a/Doc/tutorial/controlflow.rst
+++ b/Doc/tutorial/controlflow.rst
@@ -560,7 +560,7 @@
 but need to be unpacked for a function call requiring separate positional
 arguments.  For instance, the built-in :func:`range` function expects separate
 *start* and *stop* arguments.  If they are not available separately, write the
-function call with the  ``*``\ -operator to unpack the arguments out of a list
+function call with the  ``*`` operator to unpack the arguments out of a list
 or tuple::
 
    >>> list(range(3, 6))            # normal call with separate arguments
@@ -573,7 +573,7 @@
    single: **; in function calls
 
 In the same fashion, dictionaries can deliver keyword arguments with the
-``**``\ -operator::
+``**`` operator::
 
    >>> def parrot(voltage, state='a stiff', action='voom'):
    ...     print("-- This parrot wouldn't", action, end=' ')