bpo-36205: Fix the rusage implementation of time.process_time() (GH-15538)

Misc/NEWS.d/next/Library/2019-08-27-03-53-26.bpo-36205.AfkGRl.rst

+Fix the rusage implementation of time.process_time() to correctly report the sum of the system and user CPU time.
\ No newline at end of file

Modules/timemodule.c

@@ -1208,7 +1208,7 @@ _PyTime_GetProcessTimeWithInfo(_PyTime_t *tp, _Py_clock_info_t *info)
             return -1;
         }
 
-        _PyTime_t total = utime + utime;
+        _PyTime_t total = utime + stime;
         *tp = total;
         return 0;
     }