patchuserdiff.h: add missing declaration (hdr-check)

> Signed-off-by: Ramsay Jones <ramsay@ramsayjones.plus.com>
> ---
>
> Hi Junio,
>
> ... and this is the patch I needed for the current 'pu' branch.

>
> ATB,
> Ramsay Jones
>
>  userdiff.h | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/userdiff.h b/userdiff.h
> index dad3fc03c1..b072bfe89a 100644
> --- a/userdiff.h
> +++ b/userdiff.h
> @@ -3,6 +3,8 @@
>  
>  #include "notes-cache.h"
>  
> +struct index_state;
> +
>  struct userdiff_funcname {
>  	const char *pattern;
>  	int cflags;

>
> Ramsay Jones <ramsay@ramsayjones.plus.com> writes:
>
> > Signed-off-by: Ramsay Jones <ramsay@ramsayjones.plus.com>
> > ---
> >
> > Hi Junio,
> >
> > ... and this is the patch I needed for the current 'pu' branch.
>
> Which in turn means that this is to fix 5b338d60 ("userdiff.c:
> remove implicit dependency on the_index", 2018-09-15) and should be
> rolled into nd/the_index topic.