Merge branch 'diagnosticServiceCleanup' of...

Merge branch 'diagnosticServiceCleanup' of https://github.com/CyrusNajmabadi/roslyn into diagnosticServiceCleanup

src/Features/Core/Portable/Diagnostics/DiagnosticService.cs

@@ -294,7 +294,7 @@ private ImmutableArray<DiagnosticData> GetSpecificDiagnostics(Workspace workspac
 
                 AppendMatchingData(source, workspace, projectId, documentId, id: null, buffer);
                 foreach (var data in buffer)
-                    result.AddRange(new DiagnosticBucket(data.Id, data.Workspace, data.ProjectId, data.DocumentId));
+                    result.Add(new DiagnosticBucket(data.Id, data.Workspace, data.ProjectId, data.DocumentId));
             }
 
             return result.ToImmutable();