patchFixlet for argument parsing in rev-list.

> The --merge-order flag does not take parameter so there is no
> point doing strncmp with the length.
> 
> Signed-off-by: Junio C Hamano <junkio@cox.net>
> ---
> 
>  rev-list.c |    2 +-
>  1 file changed, 1 insertions(+), 1 deletions(-)
> 
> diff --git a/rev-list.c b/rev-list.c
> --- a/rev-list.c
> +++ b/rev-list.c
> @@ -462,7 +462,7 @@ int main(int argc, char **argv)
>                         limited = 1;
>                         continue;
>                 }
> -               if (!strncmp(arg, "--merge-order", 13)) {
> +               if (!strcmp(arg, "--merge-order")) {
>                         merge_order = 1;
>                         continue;
>                 }
> ------------------------------------------------
> 
>