Issue #28139: Fix messed up indentation

Also update the classmethod and staticmethod doc strings and comments to
match the RST documentation.
diff --git a/Modules/cStringIO.c b/Modules/cStringIO.c
index 5b78789..ce62f40 100644
--- a/Modules/cStringIO.c
+++ b/Modules/cStringIO.c
@@ -496,17 +496,17 @@
             Py_DECREF(it);
             Py_DECREF(s);
             return NULL;
-           }
-           Py_DECREF(s);
-       }
+        }
+        Py_DECREF(s);
+    }
 
-       Py_DECREF(it);
+    Py_DECREF(it);
 
-       /* See if PyIter_Next failed */
-       if (PyErr_Occurred())
-           return NULL;
+    /* See if PyIter_Next failed */
+    if (PyErr_Occurred())
+        return NULL;
 
-       Py_RETURN_NONE;
+    Py_RETURN_NONE;
 }
 static struct PyMethodDef O_methods[] = {
   /* Common methods: */