message: Fix perf_annotation_test compilation under gcc 8.1.1
  It fixes "unnecessary parentheses" warning/error when compiled in
  gcc8.1.1
diff: * Initiates a performance operation, storing its state in perf_var. A perf_var
  * can then be reported multiple times.
  */
  -#define PERF_OPERATION(perf_var) Envoy::PerfOperation(perf_var)
  +#define PERF_OPERATION(perf_var) Envoy::PerfOperation perf_var
  /**
  * Records performance data initiated with PERF_OPERATION. The category and description
  