[2.7] Fix misleading mentions of tp_size in comments (GH-9138)

Many type object initializations labeled a field "tp_size" in the
comment, but the name of that field is tp_basicsize..
(cherry picked from commit 0e0bc4e221f592f305d335faf5f8046484eb9238)

Co-authored-by: Peter Eisentraut <peter@eisentraut.org>
diff --git a/Modules/sha256module.c b/Modules/sha256module.c
index 8f18faa..76e5220 100644
--- a/Modules/sha256module.c
+++ b/Modules/sha256module.c
@@ -537,7 +537,7 @@
 static PyTypeObject SHA224type = {
     PyVarObject_HEAD_INIT(NULL, 0)
     "_sha256.sha224",   /*tp_name*/
-    sizeof(SHAobject),  /*tp_size*/
+    sizeof(SHAobject),  /*tp_basicsize*/
     0,                  /*tp_itemsize*/
     /* methods */
     SHA_dealloc,        /*tp_dealloc*/
@@ -571,7 +571,7 @@
 static PyTypeObject SHA256type = {
     PyVarObject_HEAD_INIT(NULL, 0)
     "_sha256.sha256",   /*tp_name*/
-    sizeof(SHAobject),  /*tp_size*/
+    sizeof(SHAobject),  /*tp_basicsize*/
     0,                  /*tp_itemsize*/
     /* methods */
     SHA_dealloc,        /*tp_dealloc*/