Fix typo in suggestion for what to do if things are broken

src/Tools/RepoUtil/VerifyCommand.cs

@@ -112,7 +112,7 @@ private bool VerifyGeneratedFiles(TextWriter writer, RepoData repoData)
 
                 if (!allGood)
                 {
-                    writer.WriteLine($@"Generated contents out of date. Run ""RepoUtil.change"" to correct");
+                    writer.WriteLine($@"Generated contents out of date. Run ""RepoUtil change"" to correct");
                     return false;
                 }