Fix typo and mark-up; shorten text

Doc/whatsnew/whatsnew24.tex

@@ -306,11 +306,9 @@ Changes to Python's build process and to the C API include:
   objN)}, constructs tuples from a variable length argument list of
   Python objects.
 
-  \item A new function, \function{PyDict_Contains(d, k)}, implements
-  fast dictionary lookups without masking exceptions raised during
-  the loop-up process (compare with \function{PySequence_Contains()}
-  which is slower or \function{PyMapping_HasKey()} which clears all
-  exceptions).
+  \item A new function, \cfunction{PyDict_Contains(d, k)}, implements
+  fast dictionary lookups without masking exceptions raised during the
+  look-up process.
 
 \end{itemize}