all: Format code to add space after C++-style comment start.

Note: the uncrustify configuration is explicitly set to 'add' instead of
'force' in order not to alter the comments which use extra spaces after //
as a means of indenting text for clarity.

extmod/modubinascii.c

@@ -248,4 +248,4 @@ const mp_obj_module_t mp_module_ubinascii = {
     .globals = (mp_obj_dict_t *)&mp_module_binascii_globals,
 };
 
-#endif //MICROPY_PY_UBINASCII
+#endif // MICROPY_PY_UBINASCII