bpo-40204, doc: Fix syntax of C variables (GH-21846)
For example, fix the following Sphinx 3 errors:
Doc/c-api/buffer.rst:102: WARNING: Error in declarator or parameters
Invalid C declaration: Expected identifier in nested name. [error at 5]
void \*obj
-----^
Doc/c-api/arg.rst:130: WARNING: Unparseable C cross-reference: 'PyObject*'
Invalid C declaration: Expected end of definition. [error at 8]
PyObject*
--------^
The modified documentation is compatible with Sphinx 2 and Sphinx 3.
diff --git a/Doc/c-api/object.rst b/Doc/c-api/object.rst
index b9c137e..a387b4a 100644
--- a/Doc/c-api/object.rst
+++ b/Doc/c-api/object.rst
@@ -291,7 +291,7 @@
is equivalent to the Python expression ``type(o)``. This function increments the
reference count of the return value. There's really no reason to use this
function instead of the common expression ``o->ob_type``, which returns a
- pointer of type :c:type:`PyTypeObject\*`, except when the incremented reference
+ pointer of type :c:type:`PyTypeObject*`, except when the incremented reference
count is needed.