reformat source code

according to code styles, 'AccessModifierOffset' should be -2.

src/sql/plan_cache/ob_ps_cache.cpp

@@ -698,7 +698,7 @@ struct ObDumpPsInfo {
 };
 
 class PsTimeCmp {
-  public:
+public:
   bool operator()(std::pair<ObPsStmtId, int64_t> left, std::pair<ObPsStmtId, int64_t> right)
   {
     return left.second < right.second;