[L0] Changed atomic value comparison

Signed-off-by: Winston Zhang <winston.zhang@intel.com>

Author: winstonzhang-intel

source/adapters/level_zero/event.cpp

@@ -833,8 +833,7 @@ urEventRetain(ur_event_handle_t Event ///< [in] handle of the event object
 ur_result_t
 urEventRelease(ur_event_handle_t Event ///< [in] handle of the event object
 ) {
-  Event->RefCountExternal--;
-  if (Event->CounterBasedEventsEnabled && Event->RefCountExternal == 0) {
+  if (Event->CounterBasedEventsEnabled && --Event->RefCountExternal == 0) {
     Event->Context->addEventToContextCache(Event);
   } else {
     UR_CALL(urEventReleaseInternal(Event));