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/python/mathutils/mathutils_kdtree.c

@@ -428,14 +428,14 @@ PyTypeObject PyKDTree_Type = {
 PyDoc_STRVAR(py_kdtree_doc, "Generic 3-dimensional kd-tree to perform spatial searches.");
 static struct PyModuleDef kdtree_moduledef = {
     PyModuleDef_HEAD_INIT,
-    "mathutils.kdtree", /* m_name */
-    py_kdtree_doc,      /* m_doc */
-    0,                  /* m_size */
-    NULL,               /* m_methods */
-    NULL,               /* m_slots */
-    NULL,               /* m_traverse */
-    NULL,               /* m_clear */
-    NULL,               /* m_free */
+    /*m_name*/ "mathutils.kdtree",
+    /*m_doc*/ py_kdtree_doc,
+    /*m_size*/ 0,
+    /*m_methods*/ NULL,
+    /*m_slots*/ NULL,
+    /*m_traverse*/ NULL,
+    /*m_clear*/ NULL,
+    /*m_free*/ NULL,
 };
 
 PyMODINIT_FUNC PyInit_mathutils_kdtree(void)