修复clang-format报错

Author: zzy

src/observer/sql/stmt/drop_table_stmt.h

@@ -19,7 +19,7 @@ class DropTableStmt : public Stmt
 
   StmtType type() const override { return StmtType::DROP_TABLE; }
 
-  const std::string                  &table_name() const { return table_name_; }
+  const std::string    &table_name() const { return table_name_; }
 
   //TODO:
   static RC            create(Db *db, const DropTableSqlNode &create_table, Stmt *&stmt);