The size of the arrays is max_key_code + 1.  This makes these functions
consistent with the other checks added for CVE-2013-1997.

Also check the XkbGetNames reply when names->keys was just allocated.
Signed-off-by: Julien Cristau <jcristau@debian.org>
Tested-by: Colin Walters <walters@verbum.org>
Reviewed-by: Alan Coopersmith <alan.coopersmith@oracle.com>
Backported-to-NX-by: Ulrich Sibiller <uli42@gmx.de>