Fix Process failing tests on OSX.

Author: Lakshmi Priya Sekar

src/Common/src/Interop/OSX/Interop.libproc.cs

@@ -546,13 +546,11 @@ internal static unsafe rusage_info_v3 proc_pid_rusage(int pid)
 
             // Get the PIDs rusage info
             int result = proc_pid_rusage(pid, RUSAGE_SELF, &info);
-            if (result <= 0)
+            if (result < 0)
             {
                 throw new Win32Exception(SR.RUsageFailure);
             }
 
-            Debug.Assert(result == Marshal.SizeOf<rusage_info_v3>());
-
             return info;
         }
     }

src/System.Diagnostics.Process/tests/System.Diagnostics.Process.Tests/ProcessTest.cs

@@ -401,7 +401,6 @@ public void Process_PrivateMemorySize64()
         }
 
         [Fact]
-        [ActiveIssue(2184, PlatformID.OSX)]
         public void Process_ProcessorTime()
         {
             Assert.True(_process.UserProcessorTime.TotalSeconds >= 0);