[PATCH:xkbcomp] Replace repeated checks for gcc with _X_ATTRIBUTE_PRINTF from xproto

[Mark Kettenis]

> From: Alan Coopersmith <alan.coopersmith at oracle.com>
> Date: Tue,  7 Jun 2011 23:55:25 -0700
> 
> Signed-off-by: Alan Coopersmith <alan.coopersmith at oracle.com>

Strangely formatted code, but that's not your fault.

Reviewed-by: Mark Kettenis <kettenis at openbsd.org>

>  utils.h |   63 +++++++++------------------------------------------------------
>  1 files changed, 9 insertions(+), 54 deletions(-)