Throw exception then TdhEnumerateProviders fails, which allows looking at the hr instead of causing an NRE which masks the exception. (#2177)

Author: desdesdes

src/TraceEvent/TraceEventSession.cs

@@ -1779,7 +1779,7 @@ internal static SortedDictionary<string, Guid> ProviderNameToGuid
                             }
                             else
                             {
-                                Trace.WriteLine("TdhEnumerateProviders failed HR = " + hr);
+                                throw new Exception("TdhEnumerateProviders failed HR = " + hr);
                             }
                         }
                     }