sync: Fix delta value check

While transitionning from CARD64 to int64, the GreaterThan call
as mistakenly been transformed into ">=". That was at least
causing problems with Mutter.

Signed-off-by: Louis-Francis Ratté-Boulianne <lfrb@collabora.com>
Reviewed-by: Adam Jackson <ajax@redhat.com>

Xext/sync.c

@@ -865,7 +865,7 @@ SyncChangeAlarmAttributes(ClientPtr client, SyncAlarm * pAlarm, Mask mask,
             ||
             (((pAlarm->trigger.test_type == XSyncNegativeComparison) ||
               (pAlarm->trigger.test_type == XSyncNegativeTransition))
-             && pAlarm->delta >= 0)
+             && pAlarm->delta > 0)
             ) {
             return BadMatch;
         }