DiffEditor: fix revert chunk for diffs of modified files

Apply chunk action doesn't make sense for that case,
will stay disabled.

Task-number: QTCREATORBUG-17136
Change-Id: Idce31b3aa9d354536a01607c10b20273158961d5
Reviewed-by: Tobias Hunger <tobias.hunger@qt.io>

src/plugins/diffeditor/diffeditordocument.h

@@ -46,7 +46,9 @@ public:
 
     DiffEditorController *controller() const;
 
-    QString makePatch(int fileIndex, int chunkIndex, bool revert, bool addPrefix = false) const;
+    QString makePatch(int fileIndex, int chunkIndex,
+                      bool revert, bool addPrefix = false,
+                      const QString &overriddenFileName = QString()) const;
 
     void setDiffFiles(const QList<FileData> &data, const QString &directory,
                       const QString &startupFile = QString());