[COMMITTED] manual: Fix strerrorname_np and strerrordesc_np return type (BZ #26343)

[Florian Weimer]

* Adhemerval Zanella via Libc-alpha:

> ---
>  manual/errno.texi | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/manual/errno.texi b/manual/errno.texi
> index 6ca566522d..7ac1554bb1 100644
> --- a/manual/errno.texi
> +++ b/manual/errno.texi
> @@ -1207,7 +1207,7 @@ to @code{errno}.
>  The function @code{perror} is declared in @file{stdio.h}.
>  @end deftypefun
>  
> -@deftypefun void strerrorname_np (int @var{errnum})
> +@deftypefun const char * strerrorname_np (int @var{errnum})
>  @standards{GNU, string.h}
>  @safety{@mtsafe{}@assafe{}@acsafe{}}
>  This function returns the name describing the error @var{errnum} or
> @@ -1218,7 +1218,7 @@ for @code{EINVAL}).
>  This function is a GNU extension, declared in the header file @file{string.h}.
>  @end deftypefun
>  
> -@deftypefun void strerrordesc_np (int @var{errnum})
> +@deftypefun const char * strerrordesc_np (int @var{errnum})
>  @standards{GNU, string.h}
>  @safety{@mtsafe{}@assafe{}@acsafe{}}
>  This function returns the message describing the error @var{errnum} or

You need to put the return type in braces because it's not a single
identifier: {const char *}

Otherwise it's not rendered or indexed correctly.