bug#12912: 24.3.50; doc string for `read-face-name'

[Chong Yidong]

"Drew Adams" <drew.adams@oracle.com> writes:

> This doc seems to be incomplete and unclear wrt DEFAULT.
>  
> It speaks of a case where DEFAULT is not a string.  It does not say what
> else it must/can be (besides nil).  Can it be a symbol - e.g., a face
> symbol?  Can it be a list of strings, i.e., multiple defaults?  A list
> of faces (symbols)?
>  
> What's more, there is nothing in the doc string that indicates that the
> face name(s) is/are read using `completing-read-multiple'.  Not that
> that implementation detail need be mentioned explicitly, but its
> _behavior_, i.e., what the behavior of `read-face-name' is, should be
> described.

Should be fixed now, thanks.