{Auto,Generic}Project: Fix setting ProjectPart::displayName

Before

    commit 8c90998fff
    CppTools/ProjectManagers: Reduce ui blocking when loading projects

the displayName was set in the ProjectPartBuilder constructor. Now this
needs to be done explicitly.

Change-Id: I67655a3a5b8052344084e467bb08efd07ab86ab4
Reviewed-by: Christian Stenger <christian.stenger@qt.io>

src/plugins/genericprojectmanager/genericproject.cpp

@@ -363,6 +363,7 @@ void GenericProject::refreshCppCodeModel()
     }
 
     CppTools::RawProjectPart rpp;
+    rpp.setDisplayName(displayName());
     rpp.setProjectFile(projectFilePath().toString());
     rpp.setQtVersion(activeQtVersion);
     rpp.setIncludePaths(projectIncludePaths());