Cleanup: PyMethodDef formatting

Missed these changes in [0].

Also replace designated initializers in some C code, as it's not used
often and would need to be removed when converting to C++.

[0] e555ede626

source/blender/freestyle/intern/python/BPy_Freestyle.cpp

@@ -509,10 +509,14 @@ static PyMethodDef module_functions[] = {
 
 static PyModuleDef module_definition = {
     PyModuleDef_HEAD_INIT,
-    "_freestyle",
-    module_docstring,
-    -1,
-    module_functions,
+    /*m_name*/ "_freestyle",
+    /*m_doc*/ module_docstring,
+    /*m_size*/ -1,
+    /*m_methods*/ module_functions,
+    /*m_slots*/ NULL,
+    /*m_traverse*/ NULL,
+    /*m_clear*/ NULL,
+    /*m_free*/ NULL,
 };
 
 //-------------------MODULE INITIALIZATION--------------------------------