atom: Bump initial table size

We're always creating ~230 atoms at startup, might as well tune it so we
don't hit the realloc path before Dispatch.

Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Adam Jackson <ajax@redhat.com>

dix/atom.c

@@ -56,7 +56,7 @@ SOFTWARE.
 #include "resource.h"
 #include "dix.h"
 
-#define InitialTableSize 100
+#define InitialTableSize 256
 
 typedef struct _Node {
     struct _Node *left, *right;