Backport of

  commit dc9ce695a69ca0787f58f8d160212a7a41acb703
  Author: Rami Ylimäki <rami.ylimaki@vincit.fi>
  Date:   Wed Mar 9 15:45:40 2011 +0200

    xkb: Initialize pad bytes sent in replies of geometry requests.

    Valgrind complains about uninitialized data being written to clients.
Reviewed-by: Erkki Seppälä <erkki.seppala@vincit.fi>
Signed-off-by: Rami Ylimäki <rami.ylimaki@vincit.fi>
Reviewed-by: Daniel Stone <daniel@fooishbar.org>
Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net>
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>