reformat source code

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

src/sql/engine/expr/ob_expr_atan.h

@@ -17,14 +17,14 @@
 namespace oceanbase {
 namespace sql {
 class ObExprAtan : public ObFuncExprOperator {
-  public:
+public:
   explicit ObExprAtan(common::ObIAllocator& alloc);
   virtual ~ObExprAtan();
   virtual int calc_result_type1(ObExprResType& type, ObExprResType& type1, common::ObExprTypeCtx& type_ctx) const;
   virtual int calc_result1(common::ObObj& result, const common::ObObj& obj, common::ObExprCtx& expr_ctx) const;
   virtual int cg_expr(ObExprCGCtx& expr_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const override;
 
-  private:
+private:
   DISALLOW_COPY_AND_ASSIGN(ObExprAtan);
 };