Apply suggestions from code review

Co-authored-by: Kumar Aditya <kumaraditya@python.org>

Author: ngoldbaum

src/c/_cffi_backend.c

@@ -288,7 +288,7 @@ static int PyWeakref_GetRef(PyObject *ref, PyObject **pobj)
 /* flags that are mutable at runtime, stored separately in ct_flags_mut to avoid
    races with ct_flags
 
-   these are read and set without using atomic operations because a lock is held
+   these are read and set without using atomic operations because CFFI_LOCK is held
    while mutating ct_flags_mut
  */
 #define CT_CUSTOM_FIELD_POS    0x00000001

src/c/realize_c_type.c

@@ -76,7 +76,7 @@ static int init_global_types_dict(PyObject *ffi_type_dict)
         return err;
 
 #ifdef Py_GIL_DISABLED
-    // Ensure that all primitive types are intitalized to avoid race conditions
+    // Ensure that all primitive types are initialised to avoid race conditions
     // on the first access.
     for (i = 0; i < _CFFI__NUM_PRIM; i++) {
         ct2 = get_primitive_type(i);