Ninja: Separate two coupled calls

Source/cmLocalNinjaGenerator.cxx

@@ -489,10 +489,9 @@ std::string cmLocalNinjaGenerator::MakeCustomLauncher(
   const std::vector<std::string>& outputs = ccg.GetOutputs();
   if (!outputs.empty()) {
     if (ccg.GetWorkingDirectory().empty()) {
-      output = this->ConvertToOutputFormat(
-        this->ConvertToRelativePath(this->GetCurrentBinaryDirectory(),
-                                    outputs[0]),
-        cmOutputConverter::SHELL);
+      output = this->ConvertToRelativePath(this->GetCurrentBinaryDirectory(),
+                                           outputs[0]);
+      output = this->ConvertToOutputFormat(output, cmOutputConverter::SHELL);
     } else {
       output =
         this->ConvertToOutputFormat(outputs[0], cmOutputConverter::SHELL);