bpo-40645: Fix ref leaks in _hashopenssl (GH-26079)

(cherry picked from commit 504ffda)

Co-authored-by: Erlend Egeberg Aasland <erlend.aasland@innova.no>

Author: miss-islington

Modules/_hashopenssl.c

@@ -2093,20 +2093,25 @@ hashlib_init_constructors(PyObject *module)
         }
         func  = PyObject_GetAttrString(module, fdef->ml_name);
         if (func == NULL) {
+            Py_DECREF(name_obj);
             return -1;
         }
-        if (PyDict_SetItem(state->constructs, func, name_obj) < 0) {
-            return -1;
-        }
+        int rc = PyDict_SetItem(state->constructs, func, name_obj);
         Py_DECREF(func);
         Py_DECREF(name_obj);
+        if (rc < 0) {
+            return -1;
+        }
     }
 
     proxy = PyDictProxy_New(state->constructs);
     if (proxy == NULL) {
         return -1;
     }
-    if (PyModule_AddObjectRef(module, "_constructors", proxy) < 0) {
+
+    int rc = PyModule_AddObjectRef(module, "_constructors", proxy);
+    Py_DECREF(proxy);
+    if (rc < 0) {
         return -1;
     }
     return 0;