on using cl-do-symbols

[Mark Oteiza]

For yuks I ported auth-source to cl-lib.  I encountered a warning I
don't quite understand when changing

  (loop for sym being the symbols of password-data
        ;; when the symbol name starts with auth-source-magic
        when (string-match (concat "^" auth-source-magic)
                           (symbol-name sym))
        ;; remove that key
        do (password-cache-remove (symbol-name sym)))

to

  (cl-do-symbols (sym password-data)
    (when (string-match (concat "^" auth-source-magic) (symbol-name sym))
      (password-cache-remove (symbol-name sym))))

The warning is that there is an unused binding for `sym'.  cl-do-symbols
does create an outer (let (sym) …) and then inside mapatoms, another
(lambda (sym) …). Does the outer let-binding in cl-do-symbols need to be there?